South Korea's prime minister resigned yesterday over the government's handling of a ferry sinking that left more than 300 people dead or missing and led to widespread shame, fury and finger-pointing, blaming "deep-rooted evils" in society for the tragedy.

South Korean executive power is largely concentrated in the president, so Chung Hong-won's resignation appears to be symbolic.

Presidential spokesman Min Kyung-wook said President Park Geun-hye would accept the prime minister's resignation.

The move comes amid rising indignation over claims by victims' relatives that the government did not do enough to rescue or protect their loved ones. Most of the more than 300 dead or missing were high school students on a school trip.

Officials have taken into custody all 15 people involved in navigating the ferry Sewol, which sank on April 16.

A prosecutor said investigators were also looking into communications between a crew member and the company that owns the ferry as the ship sank.

The prime minister was heckled by victims' relatives and his car was blocked when he visited a shelter on an island near the site of the sinking a week ago.

He told reporters in Seoul yesterday: "As I saw grieving families suffering with the pain of losing their loved ones and the sadness and resentment of the public, I thought I should take all responsibility as prime minister.

"There have been so many varieties of irregularities that have continued in every corner of our society and practices that have gone wrong. I hope these deep-rooted evils get corrected this time and this kind of accident never happens again."

Meanwhile, senior prosecutor Yang Jung-jin said that two helmsmen and two members of the steering crew who were detained on Saturday had been formally arrested. Eleven other crew members, including the captain, were arrested earlier.

Yang also said that a crew member called the ship's owner, Chonghaejin Marine Co Ltd, as the ferry was listing, but declined to disclose whether the caller was the captain.

Local media reported that the captain called for company approval of an evacuation. Prosecutors said they are analyzing the content of communications between the ship and the company.

The arrested crew members are accused of negligence and of failing to help passengers in need. Captain Lee Joon-seok initially told passengers to stay in their rooms and took half an hour to issue an evacuation order, by which time the ship was tilting too severely for many people to get out.

Divers have recovered 188 bodies and 114 people are believed to be missing, though the government-wide emergency task force has said the ship's passengers list could be inaccurate. Only 174 people survived, including 22 of the 29 crew members.

The seven surviving crew members who have not been arrested or detained held non-marine jobs such as chef or steward, Yang said.

The captain said after his arrest that he withheld the evacuation order because rescuers had yet to arrive and he feared for passengers' safety in the cold, swift water. Crew members have also defended their actions.

Despite bad weather, dozens of divers planned to continue underwater searches for the missing yesterday, said Ko Myung-seok, a spokesman for the emergency task force.

Students from Danwon High School in Ansan, a city near Seoul, made up more than 80 percent of the dead and missing. They had been on their way to the southern tourist island of Jeju.

Search complete in half of sunken ferry's compartments: Coast Guard

Divers have combed through just over half of the ferry Sewol's compartments, excluding those without passengers, a senior Coast Guard official said Sunday, as more than 100 people remained missing nearly two weeks after the deadly sinking.

Of the Sewol's 111 compartments, 47 have been excluded from the search as there is "no possibility" that passengers could be found there, Kim Su-hyeon, the chief of the Coast Guard's west regional headquarters, said in a press briefing.

"Of the 64 (remaining) compartments, 35, or more than half, have undergone a primary search," he said.

Divers planned to search three more compartments after 7 p.m., he added.

A total of 476 passengers, most of them high school students on a field trip, were aboard the Sewol when the 6,825-ton ferry capsized and sank off the southwestern island of Jindo on April 16.

As of Sunday, 188 were confirmed dead, with 114 others feared to be trapped inside the vessel.

"Putting the vessel in an upright position is difficult, and doing so could damage the bodies," Kim said. "It would be best to put the vessel in an upright position after all of the bodies have been recovered."

Kim also vowed to consider all possible methods in conducting the search operations, saying that experts from the Netherlands and other countries have been consulted.

"There have been no similar cases abroad," he said. "The experts' common view is that there is no way to overcome the strong currents in the Maenggol Channel and the low visibility there."

Search operations resumed earlier in the day after strong winds forced them to stop for nearly 11 hours.

However, the wind remained strong at a speed of 10 to 14 meters per second, while waves reached 2 meters high, hampering search efforts.

Divers were also struggling to work around various obstacles inside the ship.

"Carpets, blankets, and furniture from different parts of the ship fill up passages and cabins, making it difficult for divers to enter," Kim Suk-kyoon, the chief of the Coast Guard, said.

Officials said they plan to use wire cutters belonging to the Navy to open doors that have been shut closed by obstacles. As a last resort, they also plan to use explosives, but only with the consent of family members.

As public anger mounted over the government's poor response to the disaster, Prime Minister Chung Hong-won held himself responsible for the problems and offered to step down.

President Park Geun-hye said she would accept the resignation offer but only after the situation has been brought under control.

Families have accused the government of not having done enough to rescue the victims at the first signs of the vessel sinking. Their ire was compounded when the ship's crew, including the captain, were found to have been the first ones to flee. The government was also wrong about the number of people aboard and the number of those rescued, disrupting rescue operation plans.

Prosecutors said Sunday that they are looking into paper companies allegedly set up by the owner family of the operator of the ill-fated Sewol as part of their widening investigation into the cause of the deadly accident.

The prosecution suspects that Chonghaejin Marine Co., the ferry's operator, and Yoo Byung-eun, a billionaire whose family controls the firm, set up three paper companies to create slush funds. They said the ship was found to have been poorly inspected.

"We've found at least three companies thought to be bogus firms, which are suspected of raising funds from affiliates under the pretense of consulting costs," an investigator said.

Meanwhile, a joint team of prosecutors and police officers have referred Sewol's disgraced captain Lee Joon-seok and two other crew members to the prosecution for further investigation on charges of neglecting their duties and abandoning the passengers.

All of the 15 crew members in charge of navigating the ship have been put behind bars, accused of failing to evacuate passengers from the sinking ship and not making efforts to save the passengers.

The Coast Guard has also come under investigation on suspicion of negligence of duties.

Investigators said they plan to search the Coast Guard's situation room for material relevant to their probe. Since Saturday, they have seized material from the office of the vessel traffic service (VTS) on Jindo as well as the VTS office on Jeju.

A key focus of their investigation is expected to be whether the Coast Guard followed the manual in registering the Sewol's distress call and what measures it took to follow up.

Meanwhile, thousands of people visited a memorial altar set up at a gym in Ansan, a city just outside Seoul, on Sunday to pay their respects to the 136 students and four teachers confirmed dead.

Officials said more than 160,000 people have visited the altar over the past five days.

In Seoul, a separate altar was set up in the city center earlier in the day.

Within eight hours, more than 6,000 mourners paid their respects to the dead, officials said.