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 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.

Yoon, who was impeached and suspended from office in December, is the first sitting South Korean president to be arrested.