UN has tried to keep his peace making mission under wraps

The UN Secretary General, Ban Ki-Moon, has sent his chief of staff Vijay Nambiar, to Colombo to try to resolve the crisis.

India and human rights groups have asked Sri Lanka to extend a recent pause in the fighting to allow the civilians to leave for secure areas.

“An urgent humanitarian pause must be implemented immediately,” Amnesty International said in a statement.

More IDPs arrive

The civilians remain trapped in a strip of land along Sri Lanka's north east coast an area held by the rebels but surrounded by the army.

We remain deeply concerned about the plight of the civilian population still trapped inside the conflict zone. Those fleeing into government controlled areas provide similar accounts of the dire humanitarian conditions prevalent inside the area UNHCR statement

The Sri Lankan army says it's deploying maximum firepower against the rebels - and UN officials fear for the safety of those civilians who may be caught in the crossfire.

The UN's humanitarian chief, Sir John Holmes, has accused the Tamil Tigers of preventing people from escaping - while the rebels say civilians feel too unsafe to leave.

BBC’s UN correspondent in New York Laura Trevelyan says that the UN has tried to keep his peace making mission under wraps.

She says that, although the UN officials don't confirm, Mr. Nambiar is bound to be making contact with the government, and if he can, with the leadership of the Tamil Tigers.

Meanwhile, the UNHCR said it has stepped up its emergency response for the increased displaced in the north as a result of heavy fighting there.

“UNHCR welcomes positive steps by the government to address several protection concerns at the sites in Vavuniya. Short visits by friends and relatives to the sites are now allowed,” a statement issued on Friday said.