South Korean investigators arrested President Yoon Suk Yeol on Wednesday following a pre-dawn operation aimed at questioning the impeached leader about his brief declaration of martial law.

The Corruption Investigation Office for High-ranking Officials (CIO) had been pursuing Yoon’s arrest after he repeatedly ignored summons to appear for questioning. An earlier attempt on January 3 ended in failure after a nearly six-hour standoff with Yoon’s security team.

Wednesday’s arrest, confirmed by the CIO, marks a historic first as no sitting president in South Korea has ever been taken into custody before.

Investigators are authorized to hold Yoon for 48 hours, during which they are expected to interrogate him at their office in Gwacheon, near Seoul. To extend his detention for up to 20 additional days, the CIO would need to obtain a new warrant