All 15 crew members involved in navigating the doomed South Korean ferry which left 302 people dead or missing after sinking, are now in custody, facing criminal negligence charges.
In the latest move on Saturday, the arrests warrants were issued for two helmsmen and two members of the steering crew.
The prosecution says the 15 crew members are facing charges of criminal negligence and of failing to help passengers and requested arrest warrants for them.
The ferry with 476 people on board sank off South Korea on 16 April. Divers have recovered 183 bodies, but scores are missing presumed drowned.
Many of the victims were students and teachers from Danwon high school, south of Seoul.
On Friday, divers found 48 bodies of students wearing lifejackets in a single room on the vessel meant to accommodate just over 30 people.
The group was crammed into a dormitory and all were wearing lifejackets, a South Korean Navy officer said.
The presence of so many victims in the cabin suggested many had run into the room when the ship tilted, correspondents said.
The head of the operation to retrieve bodies said he had "no idea" how long the ship search would take.
Furious relatives have repeatedly criticised the speed of the recovery operation.
On a visit to Seoul on Friday, US President Barack Obama expressed his condolences for South Korea's "incredible loss" and offered America's solidarity.