South Korean investigators arrested President Yoon Suk Yeol on Wednesday after launching a pre-dawn operation to bring the impeached leader in for questioning over his short-lived martial law declaration.

The Corruption Investigation Office for High-ranking Officials had been looking to bring Yoon into custody after the president repeatedly defied summons to appear for questioning. CIO investigators abandoned their first attempt to arrest him on Jan. 3 after a nearly six-hour standoff due to resistance from Yoon’s security team.

Wednesday’s arrest, confirmed by the CIO, makes Yoon the first incumbent president in the country’s history to be taken into custody.

The investigators can hold the president for 48 hours and are likely to question him at their office in Gwacheon, near Seoul. The team needs to request for another warrant if they want to keep him detained for up to 20 days beyond the initial arrest.