At least 52 civilians were killed by shelling in Sri Lankan's northern war zone, the United Nations said yesterday, while a crowded hospital was hit again and Britain and the United States urged a ceasefire.

"There were 52 killed and 80 wounded from one sector," said UN spokesman Gordon Weiss, referring to the area of Suthanthirapuramin. "That was like a snapshot of the war zone." Weiss said he did not know who was responsible for shelling.

Sri Lanka's military has encircled the separatist Liberation Tigers of Tamil Eelam and is confident it will soon win a war that is one of Asia's longest-running conflicts, in which 70,000 have been killed since 1983.