We are pausing our live coverage for now - thank you for following along with us.

A reminder of the day's developments so far:

• Russian troops have withdrawn from a strategic east Ukraine town of Lyman where Kyiv's forces were threatening to encircle them
• The recapture of Lyman by Ukrainian forces has great symbolic momentum as it comes a day after Vladimir Putin announced the annexation of four partially occupied regions of Ukraine - one of which includes the town of Lyman
• Details have started to emerge of a recent deadly attack on a convoy of Ukrainian civilians. Kharkiv authorities said that 24 people, including 13 children and a pregnant woman, were shot dead in their cars by Russian troops
• Ukraine's nuclear operator says Russian forces have detained the head of the occupied Zaporizhzhia nuclear plant
• Firefighters are tackling a major blaze at a Russian military airbase in Crimea. The causes are still unknown, although Russian authorities said a plane skidded off a runway and caught fire

Today's live coverage has been brought to you by Laurence Peter, Laura Gozzi, James FitzGerald and Yaroslav Lukov.

As we reported earlier, Russia's Gazprom has interrupted its supply of gas to Italy - with no clear indication of when it will resume.

And last week, Nord Stream 1, a Russian underwater gas pipeline running across the Baltic Sea to Germany, closed indefinitely because of leaks. Russia had earlier stopped pumping gas through it.

Since the start of the invasion, EU countries have been preparing for a potential future suspension of Russian gas and oil supplies:

• The European Union has said it will cut gas imports from Russia by two-thirds over the coming year. To help it reach that goal, member states have agreed to cut gas usage by 15% over the next seven months
• EU states have looked to ship extra liquefied natural gas (LNG) in tankers from producers such as the US and Qatar - although at the moment there aren't enough LNG terminals in Europe
• EU nations will stop buying Russian crude oil imported by sea from 5 December, and end purchases of Russian refined oil products by sea from 5 February next year

Read more here.

Image source, Reuters

UK Prime Minister Liz Truss has joined other European leaders in suggesting that a series of explosions which damaged Russia's undersea Nord Stream gas pipelines were caused deliberately.

These blasts were "clearly an act of sabotage", Truss's spokesman said, following talks between the PM and her Danish counterpart Mette Frederiksen on Saturday.

Western leaders suspect that leaks discovered on the pipelines last week were the result of explosions that were caused by Russia in an attempt to ratchet up pressure on Europe over fuel supplies. The twin Baltic pipelines stretch from Russia to Germany.

Russian President Vladimir Putin accused Western countries of sabotaging the pipelines.

Russian firefighters are tackling a blaze at the Belbek military airbase in Crimea, where officials say a plane skidded off a runway and caught fire.

The base is in Sevastopol, home to Russia's Black Sea Fleet. Russia annexed Ukraine's Crimea peninsula in 2014.

The local Vesti Krim channel shows a dramatic video clip, external on Telegram, with a column of black smoke rising near the coast and what appear to be explosions.

Sevastopol Governor Mikhail Razvozhaev said that "according to rescuers, a plane on landing skidded beyond the runway and caught fire".

In August explosions rocked Russia's Saky military base in Crimea and Ukraine later acknowledged that it had hit the base with an air strike.

Ukrainian President Volodymyr Zelensky has tweeted , externalto thank his American counterpart Joe Biden for signing off a further big support package for Ukraine on Friday.

The $12.35bn (£11.08bn) of support includes both economic and military aid. It takes to $65bn the amount the US government has granted to Ukraine so far this year, AFP news agency reports.

On Friday, President Biden said he would "continue to provide Ukraine with the equipment it needs to defend itself", following Russia's announcement that it was annexing four occupied regions of Ukraine.

Hugo Bachega
Ukraine correspondent in Kyiv

Recapturing Lyman has strategic significance for Ukraine: the town had been used as a logistics hub by Russia in the east, and now could give Ukrainian troops access to more territory in the Donetsk and Luhansk regions.

The gain, which follows days of intense fighting, also carries major symbolism.

It comes a day after Russian President Vladimir Putin declared in Moscow the annexation of four partially occupied regions of Ukraine, including Donetsk - a move rejected as illegal by Ukraine and condemned internationally.

Ukraine has got the momentum in the war, and says it will go ahead with its counter-offensive to reclaim all territory under occupation.

Hours after Putin’s speech, Ukrainian President Volodymyr Zelensky released his daily address, saying: “We must liberate our entire land, and this will be the best proof that international law and human values cannot be broken by any terrorist state, even one as insolent as Russia”.

In its statement on the Russian retreat from Lyman, the Russian defence ministry said its forces had killed more than 200 Ukrainian troops in 24 hours and destroyed 14 armoured vehicles.

"Despite the losses suffered, having significant superiority in forces and means the enemy brought in reserves and pressed on with the offensive," the spokesman said.

Lyman is the first town in the Donetsk region to be recaptured by the Ukrainian army since the region was declared annexed by Russia yesterday.

More details are now also emerging about the attack on a civilian convoy in north-eastern Ukraine that we reported earlier (see our posts at 13:31 and at 12:23).

Kharkiv regional head Oleg Synehubov says 24 people - including 13 children and a pregnant woman - were shot dead by Russian troops.

Synehubov and Ukraine's SBU security service earlier said at least 20 people died, without giving the exact date of the attack.

Now Synehubov says it happened on 25 September at about 09:00 local time (06:00 GMT), quoting local police.

The details have not been independently verified.

Image source, Reuters

More now on the significance of Lyman - a strategic eastern town, which Ukraine now looks poised to recapture.

Since late May, Russian troops have transformed the town in the Donetsk region into a major logistics hub for troop deployments and ammunition supplies.

The town is also a key railway centre, connecting the Donetsk, Luhansk and Kharkiv regions in Ukraine's east and north-east.

As many as 5,000 Russian troops have been deployed in Lyman, and its recapture by Ukraine would be one of Russia's worst military defeats since the start of its invasion on 24 February.

It would allow Ukrainian troops to completely mop up the northern part of the Donetsk region and move further into neighbouring Luhansk region.

Only on Friday Vladimir Putin declared Donetsk and three other occupied regions to be part of Russia.

Russia's defence ministry says it has withdrawn Russian troops from the strategic town of Lyman in eastern Ukraine.

"Because of the threat of encirclement the allied troops have been withdrawn from Krasnyi Lyman to better positions," it says, quoted by Russian state news agencies.

Krasnyi (Red) Lyman was the old Soviet name for Lyman, which Ukrainian forces say they have entered. Russia calls its troops "allied" with local Moscow-backed fighters.

Ukrainian army gains around the town of Lyman have been hailed as a "considerable success" by an adviser to Ukraine's defence minister.

The ongoing attempt to recapture the strategic town is part of a larger counter-offensive along the eastern front line, Yuriy Sak told the BBC World Service's Newshour programme.

Sak says a Russian grouping of some 5,000 soldiers has been given the chance to surrender, claiming those fighters will be "treated better" as prisoners of war than they will be by Russia's military leadership.

He adds that "all the necessary measures" will be in place to allow any soldier who lays down his arms to be marshalled out of the embattled town.

A Ukrainian presidential adviser has rejected the latest call from Russian President Vladimir Putin for Kyiv to return to the negotiating table - saying there is no point in holding talks with those who "dance on bones".

In a tweet, external, Mykhailo Podolyak says negotiations will only be possible with a "new president of Russia" - reiterating a line from his boss, Ukrainian President Volodymyr Zelensky.

On Friday, Putin urged Ukraine to "cease hostilities and return to the negotiation table" as he announced the annexation of four Russian-occupied regions of Ukraine.

The move followed so-called referendums on those regions joining Russia - votes which were denounced by Kyiv and its Western allies as a sham. Ukrainian forces still control parts of those regions.

Paul Kirby
Europe digital editor

Image source, Getty Images

Yesterday Russia's president signed an accord to annex four Ukrainian regions. How will it work – when those areas are not fully occupied and in the middle of a war zone?

When Vladimir Putin annexed Crimea in 2014, the international community didn't recognise that either, but there was no front line on the peninsula.

Donetsk in the east is only 60% under Russian control, and Ukrainian forces are said to have encircled thousands of Russian soldiers in the strategically significant town of Lyman.

The question is: how will Putin seek to defend his annexed territories? The Kremlin says Russia will treat all of the Donetsk region as part of Russia, while those areas not under occupation will have to be "liberated". As for the south, he is unable to define where Russia will draw its new borders.

Putin is trying to mobilise enough Russians to protect front lines that stretch more than 1,000km (620 miles) and he's spoken of using all means at Russia's disposal.

Read more on this here.

Image source, Reuters

The UN's nuclear watchdog, the IAEA, has confirmed with Moscow that Russian forces detained the chief of Ukraine's Zaporizhzhia nuclear power plant - a giant facility controlled by Russian troops.

Ihor Murashov was "temporarily detained to answer questions", the watchdog told the Reuters news agency.

Murashov was allegedly arrested as he drove away from the plant on Friday afternoon, then blindfolded and taken to an unknown location.

The move prompted the UN to request "clarifications" from Russia.

The head of Energoatom, Ukraine's state nuclear agency, told the BBC that the incident happened as Russia announced the annexation of four occupied regions of Ukraine.

The Russians were allegedly trying to force Murashov to let the nuclear power plant be handed over to Russian state nuclear agency Rosatom.

"I am sure he is against it," Energoatom head Petro Kotin said.

The Zaporizhzhia nuclear complex has been under Russian occupation since the beginning of March, but Ukrainian technicians are still operating it.

The Italian multinational oil and gas company Eni has said that Russian energy giant Gazprom has informed it that "it is not able to confirm the gas volumes requested for today, stating that it’s not possible to supply gas through Austria. Therefore, today’s Russian gas supplies to Eni through the Tarvisio entry point will be zero".

Russian gas reaches Italy through the Trans-Austrian Gas pipeline network running from the Slovakian/Austrian border to the Austrian/Italian border.

About 10% of Italian gas imports originate from Russia, down from around 40% before Russia invaded Ukraine in February,

Image source, Ukraine's SBU security service

In short, not a lot.

In its announcement, Ukraine's security service SBU said the civilians in the convoy of vehicles hit by Russians in north-eastern Ukraine were shot at close range in the "grey zone" - the term used by Ukraine's military to describe the no-man's land.

But it did not specify the exact day of the attack, nor the direction the convoy was travelling when it came under fire.

The SBU said its officers were now investigating what they describe as a "war crime" committed by Russian troops.

SBU's acting head Vasyl Maliuk pledges that all the perpetrators would be punished for their "atrocities".

Russia has not commented on the reported attack, which has not been independently verified.

Adam Easton
Warsaw Correspondent

Image source, Reuters

Gas has begun flowing down a new pipeline from Norway to Poland that will give central and eastern Europe another alternative option to Russian energy.

Poland had been dependent on Russia for its gas for decades until supplies were cut off in April after it refused to pay its bills in roubles.

The opening of the pipeline and other infrastructure means Poland is no longer dependent on Russian gas.

Polish Prime Minister, Mateusz Morawiecki, said the opening of the new link marked the end of Russia’s domination and blackmail in Poland’s gas market.

The gas flow marks a historic moment for Poland.

The plan to build the pipeline was originally conceived more than 20 years ago, but successive governments gambled that Russian gas was both cheaper and reliable.

Russia’s exploitation of its status as a monopoly supplier to charge high prices, and later its annexation of Crimea in 2014 changed minds in Warsaw.

Poland then approved projects to source gas from elsewhere.

Firstly, it built a terminal to import liquefied natural gas from Qatar and the US. Now it can receive supplies directly from Norway.

Leaks from two gas pipelines between Germany and Russia that may have been the result of sabotage have raised concerns about the safety of Europe’s energy infrastructure.

Norway has stepped up security at its pipelines.

Image source, Ukraine's SBU security service

More on the reported attack on a civilian convoy in Ukraine's north-eastern Kharkiv region (see our initial post at 12:23).

Ukraine's SBU security service says Russian troops fired on the convoy of seven vehicles in late September, killing at least 20 people.

It adds that 10 of the victims were children.

The attack happened in the so-called "grey zone" between the recently liberated town of Kupiansk and the still occupied Svatove in the neighbouring Luhansk region, the SBU says.

SBU's acting head Vasyl Maliuk is quoted as saying that the "brutal attack on civilians was carried out by a sabotage and reconnaissance group".

"The enemy once again proved that its goal is the destruction of all Ukrainians, regardless of age and gender," Maliuk says.

There has been no comment from the Russians.

In the last half hour, several Russian military commentators have been posting messages on their Telegram channels saying that the Ukrainian army have either "already captured or, at a minimum, entered Lyman".

Earlier this morning, a video was posted on social media showing Ukrainian soldiers raising the Ukrainian flag at the entrance of Lyman.

"If there is a chance to defend and recapture the city, then it is incredibly small," said one Russian pro-war commentator.

Laura Gozzi
BBC News Live Reporter

Image source, Getty Images

Russian forces are thought to have used long-range air defence missiles in a ground attack role yesterday to hit a humanitarian convoy near the city of Zaporizhzhia.

Such Soviet-era missiles - named S-300 - have frequently been used by the Russian army on ground targets such as civilian infrastructure and housing, military analysts and Ukrainian officials say.

The UK Ministry of Defence says Russia’s remaining stock of "high-value" missiles is probably limited.

So why are S-300s being used against ground targets, instead of shooting down aircraft?

Justin Crump, CEO of the strategic risk company Sibylline and a former British Army officer, told the BBC that "it is a wasteful use of these missiles, and they're not particularly accurate either".

However, "the Russians have a stockpile of older missiles they need to use up. It’s a question of using everything they've got - Russia really is throwing everything but the kitchen sink at its operation in Ukraine.

"Using surface-to-air missiles to hit ground targets is an improvisation of sorts," Crump said.

"Although they have this role it's a very secondary role - it's not very effective and this is not a great use of it. The current operations, while deadly to Ukrainian civilians, still fall far short of the sort of capabilities we saw at the start of the war with Iskanders and Kalibr cruise missiles being used routinely."

Ukraine has shown it is capable of high-precision, deep strikes with HIMARS and MLRS rockets, so "Russia is trying to match it with everything it can to try and play the same game - but they're definitely playing from behind".

Despite the rudimentary nature of some attacks, it is probably going to get worse as they try to increase the pressure on Ukraine, Crump added.