The United Nations (UN) has renewed calls for a ‘humanitarian pause’ in the northern Sri Lanka conflict to enable trapped civilians to move out into areas of safety.

The UN Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, John Holmes, said his main concern was for the civilians who were not being allowed out of the area under control by the Liberation Tigers of Tamil Eelam (LTTE).

"This is an extremely worrying situation, and therefore our first appeal is to the LTTE to let the civilians out in a safe and orderly fashion," said Holmes.

Concern for civilians has heightened since Sri Lanka's armed forces captured the last road junction held by the LTTE in the first week of March, gearing towards an end to one of Asia’s longest wars – now in its 26th year.

Aid agencies estimate that around 150,000 people are trapped in the war zone, while the government says the number is no more than 70,000.

When the war finally ends, 150,000 displaced people will require humanitarian assistance from aid agencies and the Government of Sri Lanka. These include 48,000 people already accommodated in 16 displacement camps in Vavuniya in northern Sri Lanka.