South Korean police tried to search President Yoon Suk Yeol's office on Wednesday but have not been able to enter the main building, Yonhap news reported as an investigation into the U.S. ally's decision to declare martial law widened.

Former South Korean Defense Minister Kim Yong-hyun has attempted to end his own life while in custody, the head of the country’s correctional service said Wednesday, as a political crisis from the President’s brief declaration of martial law continues to spiral.

South Korean President Yoon Suk Yeol looks determined to battle on rather than step down early even as probes deepen into his martial law declaration and more members of his party say they will back impeachment.