South Korean police raided the offices of Jeju Air and the operator of Muan International Airport Thursday, as the investigation into the deadly Dec. 29 plane crash that killed 179 people ramped up.

The impeached president faces an attempt by authorities to arrest him over his short-lived Dec. 3 martial law.

The flight was carrying 181 passengers and crew when it belly-landed before slamming into a barrier, killing all aboard except two flight attendants.