SEOUL - Thousands of South Koreans began gathering in the capital for rival demonstrations on Jan 11, as investigators prepare another attempt to arrest suspended President Yoon Suk Yeol over his short-lived martial law decree.

Mr Yoon resisted arrest in a stand-off between his guards and investigators last week after his failed Dec 3 power grab plunged South Korea into its worst political crisis in decades.

Protesters both for and against Mr Yoon were scheduled to gather in sub-zero conditions along major roads in the centre of Seoul on Jan 11 – either demanding his arrest or calling for his impeachment to be declared invalid.

The country has bristled with tension for weeks after Mr Yoon directed soldiers to storm Parliament, where they unsuccessfully tried to prevent lawmakers from voting down martial law.

Since being impeached, Mr Yoon has battened down the hatches.

“Despite our efforts, he continues to evade accountability, and both the police and the CIO (Corruption Investigation Office) have really failed to act decisively,” said anti-Yoon protester and student Kim Min-ji, 25.

“It is crucial for us to raise our voices until he is removed from office.”

Mr Yoon supporter Su Yo-hahn, 71, said the sitting president’s martial law declaration which he alleged was to root out anti-state forces had “valid reasons”.

“He is someone who was elected by the people and represents our country. Saving Yoon is the way to save our nation,” said Mr Su.

Mr Yoon’s supporters were already rallying outside his residence early Jan 11 before a major demonstration set for 1pm (12pm Singapore time) in central Seoul. Separate anti-Yoon rallies were planned for 2.30 pm and 4 pm.

Mr Yoon faces criminal charges of insurrection, one of a few crimes not subject to presidential immunity, meaning he could be sentenced to prison or even the death penalty.

If the warrant is executed, Mr Yoon would become the first sitting South Korean president to be arrested.

His presidential security chief resigned on Jan 10 as he faced questioning over why his guards blocked Mr Yoon’s arrest on a day of high d...