Most missing passengers are thought to be trapped inside the sunken ferry

The South Korean coast guard searches for missing passengers at the site of the sunken ferry off the coast of Jindo Island on April 20, 2014.</p>

The South Korean coast guard searches for missing passengers at the site of the sunken ferry off the coast of Jindo Island on April 20, 2014.

JINDO, South Korea — Divers retrieved 18 more bodies on Sunday, all from inside the sunken ferry Sewol, as hopes were fading rapidly for any survivors among hundreds of people who still remained missing.

This brought to 58 the total number of people who have been confirmed dead since the 6,825-ton ferry sank off Jindo, an island off South Korea's southwest coast, on Wednesday, on its way to the southern resort island of Jeju.

Of the 476 people on board, 176 have been rescued but 244 others still remained missing. Officials believe that most of the missing are trapped inside the submerged vessel.

Navy and Coast Guard divers combing the submerged ship brought out the first body on Saturday night, and by Sunday afternoon, 15 more had been retrieved, anti-disaster officials in Seoul said.

Divers focused on searching passenger compartments of the ship. Strong currents and low visibility underwater have hampered diving operations, and officials said they will take maximum advantage of brief periods occurring a few times a day when currents slow down.

Weather in the area was relatively good on Sunday.

About 560 divers were taking turns to go underwater while 204 Navy, Coast Guard and private vessels and 34 aircraft scoured the area, officials said.

More than four days since the sinking, hopes were quickly diminishing of finding any survivors.

Earlier Sunday, dozens of angry families of those missing staged a sit-in for about two hours on this island after being blocked by police from making a protest visit to the presidential office in Seoul.

Some of them scuffled with police, shouting, "Save my children!"

Families are angry, claiming that the government mishandled the disaster and has not done enough to save possible survivors. They later met with Prime Minister Chung Hong-won for two hours for discussions on how to raise the submerged ship. Chung made no comment as he left after the meeting.

The government has been under strong public fire for bungling its initial response to the accident. Even a day after the accident, it could not give the exact number of people on board the ship.

Anger was also running high that such a high number of people are missing when there was enough time to save the passengers because it took nearly two hours for the ferry to sink. Families are also outraged that diving operations have been slow and that it took five days to pull the first body from inside the ship.

The captain and some of the sailors have also been a target of public outrage as they were among the first to leave the sinking ferry. Survivors also said that they were told to stay put where they were several times even when the ship was tilting and sinking.

Investigators looking into the disaster said Sunday that the ferry maintained radio communication with the vessel traffic service (VTS) on the island of Jindo for 31 minutes after it first sent a distress call to the VTS on the destination island of Jeju at 8:55 a.m. Wednesday.

At the start of the communication, the Jindo VTS ordered the ferry to take emergency steps to evacuate passengers, but the crew took no such measures during the communication. The communication was cut off at 9:37 a.m., and the crew appears to have immediately started escaping from the ferry, leaving hundreds of passengers behind, investigators said.

Investigators also banned 30 to 40 people, including the surviving crew members, from leaving the country, while Prosecutor General Kim Jin-tae ordered investigators to launch a probe into the ship's owner and the shipping firm Chonghaejin Marine Co. that operated the ferry.

Prosecutors said they also expanded their probe into financial scams related to the disaster

Cases of SMishing attempts were reported shortly after the accident, luring innocent people to log onto bogus news websites and reveal their personal information to be used for financial scams, the Ministry of Science, ICT and Future Planning said.

Early Sunday, the first funerals were held for students from Danwon High School in Ansan near Seoul. The three 17-year-olds were among the 325 students aboard the ship on a school trip to Jeju. Dozens of the students have been confirmed dead, and most of the missing are also students from the same school.

Funerals for two teachers were also held.

The vice principal of the school, who led the students on the ferry trip, killed himself last Friday apparently out of guilt that he has been rescued while hundreds of his students remain unaccounted for.

Also on Sunday, the government designated Ansan, home of Danwon High School, as well as Jindo, the site of the ship sinking, as special disaster zones, a move that makes them eligible for special government financial and other support for the families of the victims.

After an inexperienced third mate was found steering the ferry at the time of the sinking, police arrested the ship's 69-year-old captain, Lee Joon-seok, and two other crew members Saturday on suspicions of negligence and violation of maritime law.

An initial focus of the probe has been on suspicions that the ship made too sharp a turn for unclear reasons, leading its cargo, which has not been fastened tightly enough, to shift to one side and getting the entire ship to lose its balance.

Investigators said they have almost ruled out the possibility of the boat hitting a submerged rock.