South Korea’s impeached President Yoon Suk Yeol was formally arrested early on Sunday, days after being apprehended at his presidential compound in Seoul. He faces possible imprisonment over his ill-fated declaration of martial law last month.

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.

Hours after South Korea’s impeached President Yoon Suk Yeol was formally arrested, triggering rioting by his supporters, his lawyers said Sunday that he remains defiant in his refusal to answer questions over the probe into his declaration of martial law last month.