South Korean recovery workers strengthened a ring of netting around a sunken ferry Monday to try to prevent corpses drifting away as dive teams recovered 11 more bodies, raising the death toll to 260.

A total of 42 people remain unaccounted for, 19 days after the 6,825-tonne Sewol capsized and sank with 476 people on board -- most of them schoolchildren.

Workers in fishing boats strengthened netting around the scene of the disaster off the southwestern island of Jindo, amid concerns that powerful currents may have pulled some bodies into the open sea.

The operation followed a meeting at a Jindo harbour Sunday between President Park Geun-Hye and the relatives of passengers still missing.

They are insisting that all the bodies should be recovered before efforts begin to raise the ferry.

The search has been hampered by strong currents and waves, with dive teams working in challenging and sometimes hazardous conditions.

They must grope their way down guide ropes to the sunken ship, struggling through narrow passageways and rooms littered with floating debris in silty water.

As days go by, personal belongings and other items from the ship have been spotted further and further away, fuelling concern that some victims may never be found.

Last week bodies were retrieved up to four kilometres (two miles) away from the site, and bedding material from the ship was found as far as 30 kilometres away.

The ferry sinking is one of South Korea's worst peacetime disasters, made all the more shocking by the loss of so many young lives.

Of those on board, 325 were students from the same high school in Ansan city just south of Seoul.

Public anger has focused on the captain and crew members who abandoned the ship while hundreds were trapped inside.

There is also fury at the authorities as more evidence emerges of lax safety standards and possible corruption among state regulators.

The captain and 14 of his crew have been arrested. Prosecutors have arrested three officials from the ferry operator -- Chonghaejin Marine Co -- on charges of loading the ferry well beyond its legal limit.

North Korea offered condolences over the tragedy a week after the ferry sank, but on Monday used the incident as an opportunity to criticise Park.

She is "the very person who is responsible for the disaster", it said, adding South Korea would continue to see similar accidents unless she steps down.

The sinking was "a man-made calamity caused by... incompetence and irresponsibility" of the South Korean government, the North's official Korean Central News Agency said in a commentary.

 "As long as Park Geun-Hye, the incarnation of immorality, flunkyism and treachery... is there, nobody guarantees that a second and third 'Sewol'

disaster will not happen," it said. (AFP)