Impeached South Korean President Yoon Suk Yeol was arrested and questioned by authorities in relation to a criminal insurrection investigation on Wednesday, saying he was only cooperating with what he called an illegal probe to avoid violence.

His arrest, the first ever for an incumbent South Korean president, is the latest head-spinning development for one of Asia's most vibrant democracies even though the country has a history of prosecuting and imprisoning former leaders.

Since lawmakers voted to stand him down after his short-lived declaration of martial law on Dec. 3, Yoon has been holed up at his hillside residence, guarded by a small army of personal security that blocked a previous arrest attempt.