South Korean recovery workers have strengthened a ring of netting around a submerged ferry, in a bid to prevent corpses drifting out to open sea, as dive teams recovered 11 more bodies, raising the death toll to 259.

The latest bodies were found during a pre-dawn operation on Monday, but 43 people remain unaccounted for. It has been 19 days since the 6825-tonne Sewol capsized and sank with 476 people on board – most of them schoolchildren.

Recovery workers using fishing boats strengthened a ring of netting around the site off the southern island of Jindo, amid concerns that powerful currents may have pulled some bodies into the open sea.

“They are putting extra netting near the site to prevent the loss of bodies,” maritime ministry spokesman Park Seung-ki told a Monday morning briefing.

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

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

The search has been hampered by fast currents and high waves, while dive teams have been working in challenging and sometimes hazardous conditions.

They have to grope their way down guiding 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 concerns that some victims of the ferry disaster may never be found.

Last week, bodies were retrieved up to four kilometres away from the recovery site, and bedding materials from the ship were found as far as 30 kilometres away.

It 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 having the ferry overloaded well beyond its legal limit.