South Korea's impeached President Yoon Suk Yeol refused to appear for fresh questioning by investigators Thursday, a day after his dramatic arrest over an ill-fated martial law declaration.

South Korea looks set for a dramatic political showdown this week as impeachment proceedings kick off against suspended President Yoon Suk Yeol, who remains holed up in his fortified residence evading arrest for a separate criminal investigation.

South Korea's Constitutional Court adjourned the opening session of the impeachment trial of suspended President Yoon Suk Yeol within minutes on Tuesday, after the embattled leader did not attend court.