Australians in South Korea are being urged to avoid crowds after the nation’s president imposed martial law then lifted the order just a few hours later.

President Yoon Suk Yeol made the declaration to suspend ordinary laws and impose the military as a decision-maker late on Tuesday (local time), citing “anti-state forces” among his political opponents.

But hours later the South Korean parliament unanimously voted the ploy down, much to the delight of protesters stationed outside the national assembly.

Australia’s Foreign Affairs Department has updated travel advice due to the political crisis, although the official line remains to “exercise normal safety precautions”.

“The situation in South Korea is evolving due to developments in domestic politics,” the updated advice said.

“Avoid protests and demonstrations … sites like Gwanghwamun Square and Yeouido in Seoul may have larger crowds and more protest activity than usual.”

The situation in South Korea is evolving due to developments in domestic politics. Sites like Gwanghwamun Square and Yeouido in Seoul may have larger crowds and more protest activity than usual. Avoid protests and demonstrations. (1/3)

— Smartraveller (@Smartraveller) December 3, 2024

 Transport and other essential services might be disrupted and visitors are urged to monitor the media for updates and follow the advice of local authorities.

Finance Minister Katy Gallagher said the uncertainty should make Australian travellers cautious.

“The best message we can give on this unfolding situation is for any Australians in South Korea to really listen to official advice,” she told ABC TV on Wednesday.

“Stay away from some of the mass gatherings as we continue to get across and understand the full implications of what’s happened overnight.”

Push to impeach Yoon

Elsewhere, South Korean politicians are demanding Yoon’s impeachment after the extraordinary events of Tuesday night, which have sparked the biggest political crisis in decades in Asia’s fourth-largest economy.

A coalition of lawmakers from opposition parties said they planned to propose a bill to impeach Yoon on Wednesday, which should be voted within 72 hours.

“The parliament should focus on immediately suspending the president’s business to pass an impeachment bill soonest,” Hwang Un-ha, one of MPs in the coalition, said..

Yoon told the nation in a TV address that martial law was needed to defend the country from nuclear-armed North Korea and pro-North anti-state forces, and protect its free constitutional order, although he cited no specific threats.

Within hours, South Korea’s parliament, with 190 of its 300 members present, unanimously passed a motion requiring martial law be lifted. It was backed by all 18 members present from Yoon’s party.

He rescinded the declaration shortly after.

Protesters outside the National Assembly parliament shouted and clapped.

“We won!” they chanted, and one demonstrator banged on a drum.

SEOUL (@CNN) — 9:30AM — Mere hours after martial law ended across South Korea, demonstrators chant, “arrest Yoon Suk Yeol,” vow to stay outside the National Assembly until President Yoon resigns or is removed from office. pic.twitter.com/3w8T3OrhtR

— Mike Valerio (@ValerioCNN) December 4, 2024

After Yoon’s announcement of martial law, South Korea’s military had said activities by parliament and political parties would be banned, and that media and publishers would be under the control of the martial law command.

Helmeted troops briefly tried to enter the parliament building. Parliamentary aides were seen trying to push the soldiers back by spraying fire extinguishers.

The main opposition Democratic Party called for Yoon, who has been in office since 2022, to resign or face impeachment over the martial law declaration, the first in South Korea since 1980.

“Even if martial law is lifted, he cannot avoid treason charges. It was clearly revealed to the entire nation that President Yoon could no longer run the country normally. He should step down,” senior DP member of parliament Park Chan-dae said.

The National Assembly can impeach the president if more than two-thirds of lawmakers vote for it. A trial is then held by the constitutional court, which can confirm it with a vote by six of the nine justices.

Yoon’s party controls 108 seats in the 300-member legislature.

Protesters outside the National Assembly in Seoul after the snap martial law declaration. Photo: AAP

The crisis in a country that has been a democracy since the 1980s, and is a US ally and major Asian economy, caused international alarm.

US Secretary of State Antony Blinken said he welcomed Yoon’s decision to rescind the martial law declaration.

“We continue to expect political disagreements to be resolved peacefully and in accordance with the rule of law,” Blinken said.

There are 28,500 US troops stationed in South Korea to guard against the nuclear-armed North.

There have been more than a dozen instances of martial law being declared since South Korea was established as a republic in 1948.

In 1980, a group of military officers led by Chun Doo-hwan forced then-President Choi Kyu-hah to proclaim martial law to crush calls by the opposition, labour and students for the restoration of democratic government.

-with AAP