Jake Kwon
Reporting from Seoul

Representative Lee Seong-yoon, of South Korea's main opposition party, spoke to the BBC a short while ago from the main Assembly Hall, as he was waiting for the vote to start.

He said he had to climb over a 1.5m (4.9ft) tall fence to get into the assembly because police blocked him, even with identification that he was a lawmaker.

In case you missed it: lawmakers have voted to block the president's move to declare martial law.

We're seeing images now capturing some of the chaotic scenes both inside and outside South Korea's parliament, after the president shocked the nation by declaring martial law.

There have been reports of clashes between police and protesters outside the main parliament, with military personnel seen advancing on the entrance.

Image source, Reuters

Image source, Reuters

Image source, Reuters

Image source, Getty Images

David Oh
BBC Korean Service, reporting from Seoul

We can bring you more detail now on how South Korea's parliament voted.

National Assembly Speaker Woo Won-sik submitted a resolution requesting the lifting of martial law around 01:00 local time.

The resolution was passed with 190 of 300 members of the ruling and opposition parties in attendance, with all present in favour.

South Korea's parliament has voted to block the president's move to declare martial law, according to the Yonhap and Reuters news agencies.

We'll bring you more on this as we have it.

Jake Kwon
Reporting from Seoul

We are outside the National Assembly grounds now.

We hear can hear protesters chanting “no to martial law”, "strike down dictatorship" and "open the gate" as the sounds of sirens occasionally ring out.

Dozens of police patrol cars and riot police buses are assembled.

Rachel Lee
BBC World Service

Photos of tanks lining the streets are circulating online, sparking confusion and concern.

Ra Ji-soo, a Seoul resident, reports hearing helicopters near her home. She also shares that a friend in the police force has received an emergency mobilisation order and was on their way to the station.

Kim Mi-rim, another Seoul resident, has packed an emergency kit, fearing the situation might escalate. She recalls that previous instances of martial law involved arrests and imprisonment.

Meanwhile, journalists in Seoul are co-ordinating closely, sharing advice on how to stay cautious. With martial law in effect, all media and publishing activities will fall under strict government control.

In addition to the heavy police presence outside the South Korean parliament, we're seeing images now of helicopters circling the skies above it.

Some helicopters have landed on the parliament's roof, the AFP news agency reports.

Image source, EPA

Image source, Reuters

As large crowds gather outside the National Assembly building in Seoul, a live feed from South Korea's Yonhap news agency inside the building also shows people gathering there.

In the last half an hour, the feed captured what appeared to be a crowd of people attempting to force their way through a set of doors, as a chorus of shouting broke out.

Yonhap reports that only members of the National Assembly and other staff, as well as reporters, are being let in.

There were reports earlier that parliament's speaker planned to open a session there.

Image source, Yonhap News Agency

Jake Kwon
Reporting from Seoul

As we reported earlier, the leader of South Korea's main opposition, the Democratic Party, has called on all its members to assemble at parliament - this has now been confirmed to the BBC by Representative Hong Kee-won.

Currently, around 70 members of the opposition are inside the assembly, while the rest are gathering outside, he says.

When Speaker Woo Won-shik arrives he will call for a vote to lift the martial law, Hong says.

Hong adds that he was told special forces soldiers are inside the assembly building. It is unclear what the soldiers are doing.

We're receiving the first images now of large crowds gathering outside the South Korean National Assembly, after the country's president declared martial law.

A line of police officers appears to be guarding the entrance gate to the building, which has been closed.

Image source, Getty Images

Image source, Reuters

Image source, Reuters

The Biden administration is in contact with the South Korean government and is "monitoring the situation closely", a US national security council spokesperson tells the BBC's US partner CBS.

The US president is yet to comment on the South Korean counterpart's declaration of martial law.

We can bring you more detail now on exactly what the enforcement of martial law will mean for South Korea.

According to the Yonhap news agency, those who violate martial law can be arrested without warrant.

In addition, all media and publishers will be under the martial law command and activities. And, as we reported earlier, parliamentary activity is banned.

Medical staff, including trainee doctors, have been ordered to return to work in 48 hours, it adds.

Rupert Wingfield-Hayes
Asia correspondent

Image source, EPA

In his late night TV broadcast, President Yoon Suk Yeol said he had no choice but to resort to martial law in order to safeguard free and constitutional order.

"I declare martial law to protect the free Republic of Korea from the threat of North Korean communist forces, to eradicate the despicable pro-North Korean anti-state forces," Yoon said.

South Korea’s main opposition party leader Lee Jae-myung has condemned the move, calling it unconstitutional.

He has called on all lawmakers from his Democratic Party to converge on parliament to vote down the declaration, but latest reports from Seoul say police buses have been moved in to block the entrance to the parliament building.

The last time martial law was declared in South Korea was in 1979 after the assassination of then dictator Park Chung Hee.

John Nilsson-Wright, an associate professor at the University of Cambridge, has just spoken to the BBC World Service from Seoul, giving us a glimpse at the current mood in the South Korean capital.

While martial law usually involves restrictions on what the public can do, he says he sees no signs of the military on the streets of Seoul, and has chatted to a policeman, who he says is “as mystified as I am”.

“The streets look normal, people here are certainly bewildered,” he says. “It looked like this was simply politics of a normal sort.”

Jake Kwon
Reporting from Seoul

Image source, EPA

South Korea's main opposition, the Democratic Party, has called on all its lawmakers to assemble at the National Assembly, the country's legislative body, South Korea's news agency Yonhap reports.

Its leader, Lee Jae-myung, has called on the public to gather at the assembly, it says.

The People's Power Party leader Han Dong-hoon has called the declaration of martial law a "wrong" move, and has vowed to block it.

(As a reminder, President Yoon - who declared martial law - is also a member of the PPP).

According to South Korean law, the government must lift martial law if the majority of National Assembly demands in a vote.

The same law also prohibits martial law command from arresting lawmakers.

Image source, EPA

We're now getting reports from South Korean media that the country's military has announced the suspension of all parliamentary activity.

The Yonhap News Agency says members of the National Assembly have been banned from accessing the building.

Footage has began circulating on social media which purports to show heavy police presence outside the assembly in the Yeongdeungpo District in the South Korean capital, Seoul.

Martial law comes after wrangling over budget billpublished at 14:31 Greenwich Mean Time 3 December

14:31 GMT 3 December

Jake Kwon
Reporting from Seoul

Yoon has been a lame duck president since the latest general election when the opposition won a landslide in parliament.

He was not able to pass the laws he wanted, instead, he was reduced to vetoing desperately any bills that the opposition had been passing.

Yoon is also mired in several scandals, mainly one around his wife, who is accused of corruption. She is also accused of influence peddling. The opposition has been trying to launch a special investigation against her.

This week, the opposition slashed budgets that the government and ruling party had put forward - and the budget bill cannot be vetoed.

In the same week, the opposition is moving to impeach cabinet members, mainly the head of the government audit agency, for failing to investigate the first lady.

Yoon has gone for the nuclear option - he claims it is to restore order when "anti-state" forces he says are trying to paralyse the country.

Image source, Reuters

Yoon Suk Yeol has been South Korea's president since 2022.

He's part of the People Power Party and won the presidential election by narrowly defeating his opponent, Lee Jae-myung, by just 0.7 percentage points. This was the closest election since South Korea started direct elections in 1987.

The president has faced low approval ratings due to various controversies and scandals, including those involving his wife, such as alleged stock manipulation and allegedly accepting a luxury Dior handbag. Last month, Yoon apologised, saying his wife should have conducted herself better.

Yoon is also having a tough time pushing his agendas in parliament, which is controlled by the opposition.

The Yonhap news agency is reporting that the leader of South Korean opposition Democratic Party, Lee Jae-myung, has said the declaration of martial law is unconstitutional.

Yonhap is also reporting that Han Dong-hoon, the head of the ruling People Power Party - of which President Yoon Suk Yeol is a member - has also vowed to block the declaration, describing it as "wrong".

In brief, martial law is a temporary rule by military authorities in a time of emergency, when the civil authorities are deemed unable to function.

The implementation of martial law can have legal impacts, such as the suspension of normal civil rights and the extension of military law.

Martial law is, in theory, temporary but it may continue indefinitely.