Seoul: The captain of a South Korean ferry that sank this week was arrested on five charges, including negligence of duty and accidental homicide, as the search for hundreds of missing people continues for a fourth day.

Captain Lee Joon Seok, 69, who wasn’t on the bridge at the time of the incident, and two crew members were arrested and are being held in custody at Mokpo Coast Guard Station, prosecutor Lee Bong Chang said by phone. Captain Lee is accused of abandoning the ship and its passengers, said the prosecutor. The ship’s female third-ranked crew who was steering the ferry, surnamed Park, and a helmsman, Cho, face three charges, including accidental homicide and violation of maritime laws.

“The captain and two crew members abandoned the ship and didn’t do what they were supposed to do," prosecutor Lee said. “They should have also sailed more carefully without making sharp turns," he said, adding that the investigation is still at an early stage.

The coast guard raided the office of the ferry’s owner Chonghaejin Marine Co. in Incheon on 17 April, said prosecutor Yang Joong Jin. No company officials have been summoned for questioning yet, he said. The company didn’t answer two phone calls seeking comment.

Kim Han Shik, the 72-year-old chief executive officer of Chonghaejin Marine, said his company has committed a terrible sin. Kim was speaking at a press briefing at Incheon port 17 April that was broadcast on MBN TV.

Expansion work

Investigators are also looking into modifications made to expand passenger and cargo capacity on the 20-year-old ship, Yang said. “A full-scale probe will be conducted once the ferry is salvaged," he said.

The ferry, named Sewol, or Time and Tide in Korean, had passed safety inspections for the expansion work at a check between October 2012 and February 2013, said an official from the Korean Register of Shipping, which conducted the test. The official asked not to be identified, citing company policy.

Chonghaejin Marine had expanded the vessel’s capacity to carry an additional 117 passengers, bringing the total number of passengers and crew that can be accommodated to 956 people, the Korean Register official said.

The vessel was built by Japan’s Hayashikane Dockyard Co. in 1994 and had no accidents during 18 years of operation, according to Takaharu Miyazono, a spokesman for A-Line, the previous owner. It sold the ferry to the Korean company in October 2012, Miyazono said.

273 missing

Of the 476 people on board the ferry, 29 people are known to have died and 174 rescued, leaving 273 people unaccounted for. Investigators said earlier they are probing whether the ferry, which is now entirely submerged, turned too quickly or abnormally. They declined to say what announcements were made as the ferry sank, or whether passengers were told to stay in their cabins.

The announcements to stay on the vessel were issued because rescue boats hadn’t yet arrived, Lee, the captain told reporters in Mokpo as he was taken into custody, flanked by the two crew members. The comments were broadcast on YTN TV. “The currents were extremely fast. The water was cold, he said. Even if life jackets were worn, if we abandon the ship without a clear judgement, you can be dragged far away. I judged that there would be many complications."

Live coast guard footage of the rescue operation on Saturday showed rough seas, rain and fog in the area of the ferry, which is now marked with beige floating buoys after the ship’s bow slipped under the sea surface on Friday.

Two announcements

The ferry left Incheon, near Seoul, around 9pm local time on 15 April, after fog delayed the departure by about two-and-a-half hours, according to an Incheon port official. The ship was en route to Jeju island, a popular tourist resort in the south, in a trip that typically takes about 14 hours.

At around 8.30am and 9am the next morning, two announcements were given on the ship calling on passengers to don life jackets and stay in their current location because the ferry was tilting, crew member Oh Young Seok, 57, said in an interview on Friday at a hospital in Mokpo. Oh wasn’t on the bridge at the time of the incident and was rescued on the same boat as eight crew members.

“It’s not as though we didn’t want to help," Oh said during a break from police questioning. “We know the rule. The rule is to help the old and the weak, pregnant women, then other passengers, and then we should leave when it appears all have left, and the captain should abandon ship last. But the vessel was tilting so fast we couldn’t reach any lifeboats."

Investigators are unlikely to seek arrests for other crew members, though they will continue to be questioned, prosecutor Yang said.

First contact

The ferry first contacted authorities at 8.55am on 16 April to request coast guard assistance, according to an audio clip of the exchange issued by the ministry of oceans and fisheries.

“Ship has listed a lot. Can’t move. Please come quick," the ferry told the vessel traffic services on Jeju island, its destination.

“I did hear the announcement that we should stay put but I couldn’t," Choi Chan Yeol, a 57-year-old chef, said in an interview at a hospital in Mokpo. Choi managed to escape by gripping a cord and pulling himself to the door of the restaurant hall. “It was scary as the ferry was tilting and water was filling up."

Strong currents

More than 600 divers have been hampered in their attempts to search the sunken vessel due to strong currents and bad visibility. There have been no survivors found since the day of the sinking, which occurred off the southwest corner of the Korean peninsula.

Divers have been able to insert a guide line into the ferry that will help them enter the ship, coast guard official Ko Myung Suk told reporters on Saturday. “Early this morning, a diver saw three bodies through a cabin window before strong currents forced him back to the surface," Ko said. No bodies have been recovered from inside the vessel.

In addition to the coast guard, personnel from South Korea’s navy, air force and army are aiding the search and rescue, with 176 vessels and 28 helicopters and other aircraft supporting, the coast guard said today.

Oil has also begun to leak from the ferry and the coast guard is using 23 vessels to try to contain it, the coast guard said in a phone text message.

Most of the missing passengers are from a group of 325 students and 14 teachers from Danwon High School, who were on an excursion to Jeju island. Parents of the missing students are packed into a gymnasium on Jindo island, near the site of the sinking.

The school’s vice-principal Kang Min Kyu, who was on the ferry but survived, was found hanged behind the gymnasium on Friday, police official Lee Sung Hun told reporters.

The ferry listed and capsized in an area of the ocean as shallow as 20 metre (66 feet) in some parts, based on readings from a coast guard vessel used in the rescue operation. Bloomberg

Kiyotaka Matsuda in Tokyo contributed to this story.