Britain sends envoy to UN over Sri Lanka

LONDON, April 18 (Reuters) - Britain said on Saturday it was gravely concerned about fighting between government forces and Tamil separatists in Sri Lanka and had sent an envoy to the United Nations for urgent talks.

Foreign Secretary David Miliband said the conflict in northern Sri Lanka threatened many thousands of civilian lives and repeated his call for an immediate ceasefire to allow civilians to leave the conflict area.

"The U.N. are making progress with the government of Sri Lanka towards an agreement to get support to civilians in the conflict zone and on efforts to get agreement from the LTTE to allow civilians to leave," Miliband said in a statement.

"The prime minister's special representative, Des Browne, is travelling to New York to consult urgently with the U.N.."

Sri Lanka gained independence from Britain in 1948.

Hundreds of Tamil Tiger supporters demonstrated outside Britain's parliament this month calling for London's help in securing a ceasefire between Sri Lankan forces and Tiger separatists.

The United Nations says tens of thousands of people are being held as human shields by the LTTE, and has urged the Sri Lankan military to protect them during a final offensive. (Reporting by Kate Kelland; editing by Robert Woodward)