South Korean authorities attempt to arrest President Yoon for second time - standoff with security service under way

A new attempt to arrest South Korean President Yoon Suk Yeol is under way, six weeks after his short-lived attempt to impose martial law.

Police have been trying to access the president's official residence to detain him - but doing so has, once again, proven difficult.

A standoff - watched by thousands of pro- and anti-Yoon protesters - started before dawn outside the hillside villa between authorities and the president's security service.

Hours later, hundreds of police officers made it into the grounds of the property by using ladders to climb over barriers.

Security staff had fortified the building ahead of the latest arrest attempt, creating a "barrier" inside the gates by parking buses and large vehicles against them at about 5am on Wednesday local time (8pm Tuesday, UK time).

The furore is unfolding in front of protesters both for and against the South Korean president. Many of his supporters are waving glowsticks and singing, and officers - some carrying wire cutters and ladders - battled through the crowd to the residence's gates.

Mr Yoon's lawyer Yoon Kab-keun, who was carrying papers, could be seen talking to investigating officials in front of the residence, while some ruling party lawmakers formed a human chain to block them.

After attempting to breach the barricades at the front of the compound, officials tried to access the residence from the back, according to local media.

They later made it into the grounds by using ladders to climb over rows of buses parked by the president's security services.

Officers were then seen moving up the hilly compound - but they may face more obstacles as they approach the main building.

Police said they had deployed 3,200 officers to execute the arrest warrant.

Amid the standoff, one person who collapsed has been transported away from the scene by the fire department, local media said.

South Korean investigators said they were not considering Mr Yoon's offer to voluntarily appear for questioning and said they still aim to arrest him, the Yonhap news agency reported.

Later in the day they arrested the acting chief of the presidential security service, Kim Sung-hoon, for blocking their initial attempt to arrest Mr Yoon earlier this month, the agency also said.

Mr Yoon's presidential security service prevented dozens of investigators from arresting him after a standoff lasted nearly six hours on 3 January.

After the authorities' first attempt at detaining the president, new barbed wire and additional barriers were installed at the property.

The Corruption Investigation Office for High-Ranking Officials and police responded by pledging more forceful measures to detain Mr Yoon while they jointly investigate whether his martial law declaration on 3 December amounted to an attempted rebellion.

The National Police Agency convened multiple meetings of field commanders in Seoul and nearby Gyeonggi province in recent days to plan their detainment efforts, and the size of those forces fuelled speculation that more than 1,000 officers could be deployed in a possible multi-day operation.

Anti-corruption agency and police officials met representatives of the presidential security service on Tuesday morning for unspecified discussions regarding efforts to execute the detention warrant for Mr Yoon.

It was not immediately clear at the time if any kind of compromise was reached.

What happened on 3 December?

Mr Yoon declared martial law and deployed troops around the National Assembly at the beginning of last month.

It lasted only hours before politicians managed to get through the blockade and voted to lift the measure.

His presidential powers were suspended when the opposition-dominated assembly voted to impeach him on 14 December, accusing him of rebellion.

Mr Yoon has argued his declaration of martial law was a legitimate act of governance, calling it a warning to the main liberal opposition Democratic Party which he has described as "despicable pro-North Korean anti-state forces".

He claimed the party used its legislative majority to impeach top officials and undermine the government's budget.

Over the past two weeks, thousands of anti-Yoon and pro-Yoon protesters have gathered daily in competing rallies near his office in Seoul, in anticipation of the second detention attempt.