South Korea plunges into political crisis

President Yoon Suk Yeol declared martial law on Tuesday night in a move that stunned South Koreans and triggered a short-lived attempt by troops to enter parliament, as lawmakers and protesters quickly voiced opposition to the most serious challenge to the country's democracy since the 1980s.

However, in a late-night statement, the president said he would lift martial law, just hours after imposing it in a bid to quell what he called "anti-state forces". Yoon backed down after lawmakers voted to oppose the unexpected declaration, which caught even South Korea's closest allies around the world off guard.

Earlier the National Assembly was sealed and troops entered the building for a short time, while hundreds of protesters gathered outside chanting: "arrest Yoon Suk Yeol" and faced off with security forces.

"Just a moment ago, there was a demand from the National Assembly to lift the state of emergency, and we have withdrawn the military that was deployed for martial law operations," Yoon said in a televised address around 4:30 am (1930 GMT Tuesday).

"We will accept the National Assembly's request and lift the martial law through the Cabinet meeting."

The U-turn prompted jubilation among protesters outside parliament who had braved freezing temperatures to keep vigil through the night in defiance of Yoon's martial law order.

Some 190 lawmakers had managed to get in to the assembly in the early hours of Wednesday, where they unanimously voted in favour of a motion to block the martial law declaration and call for its lifting.

The speaker of parliament declared the martial law announcement invalid and lawmakers early on Wednesday voted to reject it. Yoon's move, which he cast as aimed at his political foes, was vocally opposed even by the leader of his own party, Han Dong-hoon, who was present for the vote in parliament and who has clashed with Yoon over the president's handling of recent scandals. Earlier, live television footage showed helmeted troops apparently tasked with imposing martial law attempting to enter the assembly building, and parliamentary aides were seen trying to push the soldiers back.