SEOUL, Dec 5 (Reuters) - 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.