The captain of a South Korean ferry that sank this week said he delayed giving evacuation orders because he feared passengers would "drift away".
Lee Joon-seok, 69, was arrested with two crew members on Friday.
He has been criticised for not giving orders to evacuate soon enough.
Divers reported seeing three bodies in the ship on Saturday but were not able to retrieve them. The number of missing stands at 273 with 29 confirmed dead. Some 174 passengers were rescued.
Rescue operations are continuing for a fourth day but officials say visibility is poor and strong currents are making the work difficult.
The captain faces charges including negligence of duty and violation of maritime law.
Investigations are focusing on a sharp turn the vessel took before it started listing and whether an evacuation order could have saved lives.