South Korea's impeached President Yoon Suk Yeol refused to be questioned by investigators on Monday under a probe into whether he committed insurrection, as dozens of his supporters faced being charged over a violent rampage on a court building.

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

South Korea's impeached President Yoon Suk Yeol had his mug shot taken and underwent a physical check before spending his first night in jail as a criminal suspect, a prison officer said Monday.