Heavy fighting has been reported between the Sri Lankan military and Tamil Tiger rebels around a strategic base.

Both sides are claiming victories, but there has been no independent account of the battles.

The Sri Lankan defence ministry said a rebel attack on the Elephant Pass military complex had been repulsed on Saturday and that 230 rebels had been killed.

It said that on Sunday, further Tamil Tiger attacks around Elephant Pass had also been defeated, claiming another 16 rebel lives.

But the rebels' radio station, Voice of Tigers, reported that two of the three bases that form the Elephant Pass complex had been captured.

A statement issued by the Tamil Tigers said: "[We] wish to deny categorically the government's claim that over 200 of our cadres have been killed at Vettilaikerni.

"This is part of the malicious disinformation campaign of the Sri Lankan military."

Civilian casualties

There has been an upsurge in fighting between government and rebel forces in recent weeks.

Last month, the Tigers captured a large area of land, over-running several army bases in the Wanni region, and inflicting one of the most serious defeats on the government since the start of the conflict.

In one incident, 44 Tamil refugees were killed when shells hit a 400-year-old Catholic Church. The government and rebels blamed each other.

The humanitarian organisation, Medecins Sans Frontieres (MSF) has contacted both rebels and government to express its concern for the civilian population.

MSF, which on Friday received the Nobel peace prize, said indiscriminate attacks by artillery and aerial bombing of areas with civilian populations had resulted in numerous casualties.

The organisation also asked both sides to stop using land mines, which it said were causing injuries to local residents and restricting access to affected areas.

"Unless such restrictions are stopped, the civilian population will continued to suffer from shortages of medical care, food and shelter materials," the statement said.