The Tigers said meanwhile that at least 15 more civilians were killed in new shelling near Muttur, the flashpoint Muslim-majority town where a dispute over water supplies set off the latest round of violence two weeks ago.
As the fighting raged despite warnings of all-out war, the French aid group Action Against Hunger (Action Contre la Faim, ACF) said it found the corpses of 16 Sri Lankan members of its staff in the city.
Aid officials said they were not in a position to say how the staffers had been killed, but several witnesses who saw the bodies Sunday said they had been shot dead.
ACF said it was suspending its mission to Sri Lanka following the killings.
"These humanitarian workers were clearly identified by their T-shirts as members of a non-governmental organisation," said group director Benoit Miribel.
"Their deaths are unacceptable, and show that barbarity is winning the battle against solidarity.
"
The European Commission said it was "deeply shocked" by recent attacks on