South Korean President Park Geun-hye said on Monday the actions of the captain and crew of a ferry that sank last week with hundreds feared dead were tantamount to murder, as authorities arrested four more officers of the vessel.
Sixty-four people are known to have died and 238 are missing, presumed dead, in the sinking of the Sewol ferry last Wednesday. Most of the victims are high school children.
Captain Lee Joon-seok, 69, and two other crew members were arrested last week on negligence charges, with prosecutors announcing four further arrests - two first mates, one second mate and a chief engineer - on Monday.
Several crew members, including the captain, left the ferry as it was sinking, ahead of the passengers, witnesses have said.
Park said the crew's desertion was tantamount to murder.
"Above all, the conduct of the captain and some crew members is unfathomable from the viewpoint of common sense, and it was like an act of murder that cannot and should not be tolerated," Yonhap news agency quoted her as saying during a meeting with aides.
Lee, the captain, said in a promotional video four years ago that the journey from the port city of Incheon to the holiday island of Jeju was safe - as long as passengers followed the instructions of the crew.
He also told a newspaper that he had been involved in a sea accident off Japan years before.