Fishermen retrieved the body of a passenger of the sunken South Korean ferry about 2 kilometers (1.2 miles) away from the vessel, fueling fears that other victims may have drifted away from the disaster site.

By late Thursday evening, the confirmed death toll had risen to 221 as a total of nine bodies were brought ashore. Divers continued to struggle against choppy seas, poor underwater visibility and strong currents in the search for the 81 people still missing.

After the Sewol sank on April 16, nets were cast around the sunken vessel to prevent bodies from drifting out to sea. But as the search moves into its third week, officials have acknowledged that some victims’ bodies may never be found.

Prime Minister Chung Hong-won on Thursday visited the gymnasium near the ship site, where many family members of the missing are staying. He told the relatives that he had enlisted the help of fishermen to prevent bodies from being swept away, according to local news reports. The body retrieved by fishermen was found on Wednesday but the news was released by rescuers on Thursday.

In a reminder of the risks facing those in the round-the-clock rescue effort, a 40-year-old diver was taken to a hospital early Thursday after losing consciousness because of decompression sickness. After five hours of treatment at a local hospital, he regained consciousness and was in stable condition but continued to receive treatment, a hospital official said.

Divers continued to work through the upper decks of the ship, where most of the passengers are thought to have been when the ferry sank. Obstacles such as loose furniture have slowed the search.

Under pressure from family members who have been demanding accelerated work, rescuers deployed a diving bell, which allows divers to stay underwater longer, but it was later withdrawn. Officials said it wasn’t suitable for use in the strong currents near the ship.

Meanwhile, as South Korean businesses and government offices closed for the May Day holiday, hundreds of people visited a park that has become a mourning site in the city of Ansan, near Seoul. A large altar was set up and photos of the dead were displayed on the wall.

Television footage showed mourners placing bouquets of white chrysanthemums tied with yellow ribbons at the altar as they bowed their heads and prayed. Most of the passengers on the ship were students from a high school in Ansan. More than 200,000 people have already visited the memorial, with others set up across the country.

Local media also reported prosecutors searched the offices and homes of executives of businesses connected with the family that controls the operator of the ferry on Thursday. Prosecutors couldn’t be reached for comment.

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