South Korean prosecutors have opened an investigation into President Yoon Suk Yeol, his interior minister, and the now-former defence minister over their roles in an attempt to impose martial law, Yonhap news agency reported on Thursday.
Kim Yong-hyun, who resigned as South Korean defence minister over his involvement in Tuesday's martial law order, also faces a travel ban as prosecutors investigate, Yonhap said. The other two do not face such bans.
Citing unspecified threats from "anti-state forces" and obstructionist political opponents, Yoon imposed martial law for about six hours before reversing course after parliament voted to oppose the move.
Yoon now faces an impeachment vote on Saturday.

Powerful winter storm shuts schools, disrupts travel across US Northeast
At least 19 killed in Nepal bus crash
Mexican military kills cartel boss 'El Mencho' in US-backed raid
Afghanistan says Pakistan strikes kill and injure dozens
Police officer killed, dozens injured in bomb explosions in Ukraine's Lviv