Home Secretary Amber Rudd will provide an update following a meeting of the government's Cobra emergency committee, our political correspondent Leila Nathoo reports from Whitehall.

The meeting lasted around 45 minutes and is the second held since yesterday morning's bomb at Parsons Green station.

Image source, Getty Images

Police investigating the Parsons Green bombing have good CCTV images and are "pleased" with the progress of the investigation, BBC Home Affairs Correspondent Daniel Sandford says.

Police have arrested an 18 year-old man in connection with the South West London attack.

He says police believe that the bomb is linked to Islamist terrorism.

The Times

Writing in The Times,, external crime and security editor Fiona Hamilton says that the Tube bombing at Parsons Green station is an important reminder of how vulnerable the transport network is.

While security has been improved since the 7 July in 2005, "a network with huge numbers of passengers can never be made 100% safe".

The Guardian

The Guardian suggests, external the incompetence of terrorists has spared hundreds of lives in recent years.

Before the improvised explosive device that failed to detonate fully on the tube train at Parsons Green, there have been many other bungled attempts to kill or maim people - including a world-be suicide bomber who set off his own device in a toilet.

Eliminating key individuals with high levels of expertise will help stop knowledge of destruction passing to potential attackers, the paper says.

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Metropolitan Police Commissioner Cressida Dick has joined police officers on the streets of London to highlight the increased visible presence in the capital.

She went by Tube to Waterloo Station and patrolled along the South Bank with colleagues.

"Yesterday we saw a cowardly and indiscriminate attack which could have resulted in many lives being lost," said the commissioner.

"Again we saw a quick response from all the emergency services and transport staff.

"Since then, we have had teams of detectives and specialists working through the night on the investigation and officers throughout London mobilising and providing an increased visible police presence - especially in crowded places.

"London has not stopped after other terrible attacks and it will not stop after this one."

She added: "It is a simple message, but a powerful one, to see London getting on with its business enjoying the weekend and everything the city has to offer.

"You can help us by remaining vigilant and letting us know if you have any concerns."

BBC News Channel

Independent defence analyst Andy Oppenheimer told BBC News that experts were no longer calling people carrying out these attacks "lone wolves", but now referring to them as "self-starter cells".

But he said there was little solace in the amateur nature of the incident.

"I don't think we can take too much comfort because there is so much going on that is very random, such as learning from the internet, which may produce faulty recipes for bomb making," he said.

"If they are self-starting and they are learning as they go along, there will be more botched attempts, but that doesn't mean people won't get hurt by them because devices are so volatile.

"They may be teaching themselves, they maybe passing on bits of information... it is not full training in the way the IRA did. But they can teach each other and they can be trained as they do learn quickly, even when they are doing it in a random way."

The Daily Telegraph

Writing in the Daily Telegraph, external, Raffaello Pantucci, director of international security studies at the defence think tank Rusi, says attacks on public transport strike at the heart of cities and damage the economy.

While it is impossible to guarantee complete security, he says initiatives such as public awareness campaigns, as well as authorities staying on top of the terrorist threat, mean the UK is seeing only relatively limited impact events.

A meeting of the government's Cobra emergency committee has ended with the recommendation that the UK terrorist threat level remains at "critical".

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Robin Smith, British Transport Police Assistant Chief Constable, is urging the public to be "alert but not alarmed".

"Code critical is a well-rehearsed plan now, regrettably of course," he tells the Press Association.

Officers from the City of London, Metropolitan and British Transport police forces are working together under Project Servator, a counter-terror and crime strategy introduced in 2015.

It involves both uniformed and undercover officers out on the streets trying to spot those scoping sights for attacks and other crimes..

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Professor Michael Clarke adds the objective of Operation Temperer is to free up police officers so that they can be out protecting the public.

Unlike France, he says, people in the UK are not reassured to see armed military personnel on the streets. They would rather see police officers.

Operation Temperer, where the military are deployed to support police officers, is being stepped up gradually, BBC Special Correspondent Robert Hall says.

Former director general of the Royal United Services Institute, Professor Michael Clarke, tells the BBC this operation can put up to 5,000 military personnel on notice to serve.

Usually, however, only a few hundred are deployed to guard facilities out of sight to the public but supported by police.

This includes infrastructure such as nuclear power stations.

Looking at the investigation, former head of the National Counter Terrorism Security Office, Chris Phillips, says the presence of a timer on the bomb indicates the bomber did not intend to commit suicide.

He wonders if the mixture in the bucket in a cool bag on the Tube was not the finished device, but preparations for it.

The mix needs to be kept cool, he says. And detectives may be looking at whether the bomber may have panicked when that mixture began to bubble, and tried to get rid of it.