Japan, China watching for S Korean bodies

South Korea will ask Japan and China to inform it about any bodies that wash up on beaches, an official says, as fears grow that some victims of a ferry disaster may never be found.

Divers trying to search the wreck of the upturned Sewol, which capsized on April 16 with 476 people on board, have been frustrated on Monday for a third straight day of atrocious weather and dangerous conditions.

Despite more than 60 hours of operations since Friday, only two more bodies have been recovered, leaving 113 still unaccounted for.

The confirmed death toll from one of the country's worst ever maritime disasters stood at 189 on Monday. Most of the missing and dead were high school students.

Strong currents and stormy weather have hampered the search of the wreck and worsened fears that bodies could drift free and be scattered.

A series of nets have already been thrown up in seas around the ferry but no finds have yet been reported.

Park Seung-Gi, a spokesman for the government's Joint Task Force which is co-ordinating actions, vowed Monday to redouble efforts to prevent bodies getting lost at sea.

Special teams have been set up to search underwater around the sunken vessel, as well on the sea surface, nearby islands and shores, he said.

"We will try our best to find bodies by using all our resources including helicopters, warships, patrol ships and search personnel," Park told reporters.

The search will concentrate on an area within a radius of 40-60 kilometres from the wreck,

Officials planned to ask two neighbouring nations - China and Japan - to contact Seoul if they find any unidentified bodies on their shores.

"It may be too early (to ask) as bodies can't drift that far at the moment... but I think we have to move preemptively," he said.

In deeply Confucian South Korea, the proper burial of bodies - often in the deceased person's home town - is considered a way to show respect for the dead and to allow their soul to rest in peace.

Twelve days on from the disaster, divers have only been able to search around a third of the 111 cabins on the sunken ferry.

Waterlogged debris, cramped conditions and poor visibility is making their gruesome task very difficult, say officials, with several frogmen reporting injuries or decompression sickness.