Twelve more bodies were retrieved from the sunken ferry Sewol on Monday, raising the death toll to 262 and lowering the number of those missing to 40, 19 days after the ship sank off South Korea's southwest coast.
Divers have completed an initial search of 61 of the 64 compartments where people are expected to be found, officials said.
The Sewol has a total of 111 compartments.
After combing through the compartments, divers plan to search public spaces such as lobbies, staircases, shops, arcades and bathrooms.
If the missing are not found by May 15, the rescue team plans to expand the search to the cargo compartments on the first and second decks, officials said.
The 6,825-ton Sewol was carrying 476 passengers when it capsized and sank off the southwestern island of Jindo on April 16.
Most of the passengers were high school students on a field trip to the southern resort island of Jeju.
It is still possible that an infant was aboard the ship but excluded from the list of passengers, Ko Myeong-seok, a spokesman for the government's emergency task force said.
"Of the women who are missing, there are two who could have had young children, judging from their age," he said. "However, it has not been confirmed whether they boarded with a baby."
The Coast Guard began to look into the possibility after a civilian diver claimed to have spotted a baby bottle in the stern of the ship on April 21, he said. The bottle has not been retrieved.
Had an infant boarded the ship, it is highly likely that the child was omitted from the passenger list as children under the age of 2 are not required to buy a ticket.
Officials also said they were installing more stow nets and tow-boat trawls closer to the site of the sinking to prevent bodies from being swept away from the vessel.
More than 750 articles of what appeared to be the victims' personal belongings have been retrieved from near the site, they said.
Mourners, meanwhile, visited memorial altars across the nation to pay their respects to the dead. Children could be spotted with their parents as Monday was a public holiday. May 5 is celebrated as Children's Day in South Korea.
According to an official government tally, more than 1.15 million people have visited altars across the nation since the first one was set up a week after the accident. About 30 percent of the mourners, or 360,000 people, paid tribute at the government's official mourning altar in Ansan, just south of Seoul.
Ansan is home to Danwon High School, which lost hundreds of students and teachers in the sinking.
As of Monday, the altar in Ansan enshrined the portraits and nameplates of 213 people, including 185 students and four teachers of Danwon.
Investigators looking into the sinking apprehended a senior official of the Sewol's operator, Chonghaejin Marine Co., on suspicion of accidental homicide and accidental sinking.
The suspect, surnamed Kim, is accused of not taking appropriate measures even though he was aware that the vessel was overloaded.
So far, the ship's captain, Lee Joon-seok, and 14 other crew members as well as three other officials of Chonghaejin Marine have been arrested in connection with the accident.
Preliminary investigations showed that the ferry took only 580 tons of ballaster water which is far below the 2,023 tons required under rules, apparently to carry more cargo for profits.
Meanwhile, the oil spill from the sunken ferry is also emerging as another problem as it started to affect nearby seaweed farms.
Of the estimated 214 kiloliters of fuel oil the ferry was carrying at the time of the accident, 206 kiloliters have been retrieved safely, coast guard officials said. (Yonhap)
