Voicing concern about Sri Lankan civilians caught in the crossfire between government troops and the Liberation Tigers of Tamil Eelam, the United Nations has sought an immediate cessation of hostilities.

It also called for unimpeded access to humanitarian agencies to enable them to take care of thousands of people who have fled to escape the conflict.

The UN refugee agency said it is particularly concerned about reports of deliberate displacement of particular communities as also information that thousands of people are trying to flee the northeastern town of Muttur.

However, it said the fighting has caused displacement, injury and loss of life and property amongst all ethnic communities.

UN Secretary General Kofi Annan has also called for a ceasefire and resumption of peace talks.

'The parties have the primary duty and responsibility to provide protection and humanitarian assistance to internally displaced persons,' the refugee agency said.

'This includes protection from displacement, protection during displacement and protection during return, resettlement and/or reintegration.'

The agency called for an immediate cessation of hostilities and unimpeded access to humanitarian agencies to enable them to take care of thousands of people who have fled to escape the conflict.

Late last month, High Commissioner for Refugees Antonio Guterres visited Sri Lanka [Images] and urged both sides to support confidence-building measures to prevent the displacement of people in the first place and allow them to return home if they chose.

Since a 2002 ceasefire began to fray in April this year, some 50,000 people have fled their homes and are living in neighbouring communities in Trincomalee, Batticaloa, Puttalam and in the north of the country, the UN said.

Over 5,600 people have fled the country to Tamil Nadu since January, according to the refugee agency, which has been working in Sri Lanka since 1987.

More than 312,000 people have been displaced within the country since the conflict erupted in 1983 between the government and the LTTE. The UN refugee agency assists about 67,000 displaced people in welfare centres throughout the country.