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.

SEOUL (Reuters) - A South Korean court granted on Sunday an extension of President Yoon Suk Yeol's detention, saying there was "concern" that Yoon could "destroy evidence" in a criminal probe related to his short-lived declaration of martial law in early December.

As South Korean authorities extended President Yoon Suk Yeol's detention, his supporters stormed the courthouse that issued the warrant, smashing windows with police shields.