South Korea’s impeached president, Yoon Suk Yeol, was detained in a major law enforcement operation at the presidential compound Wednesday, defiantly insisting the anti-corruption agency didn’t have the authority to investigate his actions but saying he complied to prevent violence.

President Yoon Suk Yeol was arrested and taken for questioning after more than 3,000 police officers marched on his residence in the early hours of Wednesday.

The development, which followed a failed arrest attempt earlier in January, deepens the fallout from his short-lived declaration of martial law last month.