Sri Lankan soldiers sort the belongings of students at a school which came under artillery attack by Tamil Tigers in the North Eastern village of Kallaru, 7 Dec. 2006

The United Nations has expressed concern about the plight of civilians in Sri Lanka caught in the crossfire between Tamil Tiger rebels and the military. As Anjana Pasricha reports from New Delhi, hundreds of civilians have been killed in the fighting, and thousands displaced.

In a statement on Tuesday, the United Nations called for the protection of "desperate civilians" in Sri Lanka. They are trapped in areas where Tamil Tiger rebels and the military have been engaged in intense fighting in recent weeks. The U.N. has called on both sides to stop indiscriminate shelling of civilian areas, saying this is resulting in deaths, injuries and forced evacuations.

The immediate area of concern is Batticaloa district where the rebels and the military have fought several battles around the rebel-held town of Vakarai.

Davide Vignati, at the International Committee of the Red Cross, says thousands of people have been forced to flee their homes to escape the fighting.

"The most critical situation is in Vakarai," he said. 'We have more than 30,000 displaced people, and these people are surviving only thanks to the support of humanitarian organizations. A humanitarian convoy provides them with food and drinking water."

The rebels say dozens of civilians have been killed in recent days in army artillery fire around the town. Officials admit civilians have been killed, but accuse the rebels of using them as human shields, and of positioning artillery in civilian areas. The guerrillas deny the charges.

Humanitarian groups are also battling to assist about 60,000 refugees in two other areas subject to intense fighting in the past year: the northern army-held Jaffna district, and the northeastern Trincomalee district. Many civilians have taken shelter in schools and temples; others are living in temporary camps.

The situation is particularly grim in Jaffna where the government has tried to isolate the rebels by blocking the only highway that connects this district to the mainland. As a result, the supply of essential goods has been reduced to a trickle, intensifying shortages of food and fuel. Davide Vignati says the situation is critical.

"Prices are growing, there is shortage of some items but we cannot see any immediate problem of starvation. They cannot carry out their normal activities," he explained.

Truce monitors say civilian casualties account for more than one-third of the total this year, after both sides resumed fighting in violation of a 2002 truce. Three thousand four hundred have died, 1,200 of them civilians.

The renewed fighting follows four years of relative peace when the rebels and the government were pursuing peace negotiations. The rebels have been fighting for a homeland for the minority Tamil community since 1983.