Sri Lanka says 25 dead in clashes amid calls for UN rights mission

International groups called for a UN human rights monitoring mission in Sri Lanka on Saturday as fresh clashes between troops and Tamil Tiger rebels left at least 25 dead, the government said.

Fighting across Sri Lanka's northern frontier left 24 rebels dead and injured 18 during 24 hours ending early Saturday, the defence ministry said, placing their own losses at one soldier killed and two injured.

There was no immediate word from the Liberation Tigers of Tamil Eelam (LTTE). Independent verification of battlefield casualties are not possible and both sides are known to offer wildly contradictory figures.

Amnesty International and Human Rights Watch Saturday called for the United Nations Human Rights Council to monitor rights abuses in Sri Lanka.

They have called before for such a mission but said the need was more urgent than ever.

The human rights situation in Sri Lanka "is rapidly deteriorating. In the last two weeks of November alone, more than 50 civilians have been killed in Sri Lanka," the Human Rights Watch said.

Since September, more than 20,000 people have been displaced by the escalation in fighting between both sides, the rights group said in an open letter ahead of a UN meeting on human rights in Geneva next week.

In the northern district of Jaffna, the number of "enforced disappearances" and unlawful killings continues "at very high levels," the HRW said adding that "over 200 civilians were reported missing in Jaffna since January 2007."

"Both the Sri Lankan government and the LTTE have failed to abide by their obligations under international humanitarian law to protect civilians from harm," the group said.

Sri Lanka has strongly resisted calls for a UN monitoring mission in the embattled country where more than 60,000 people have been killed since 1972.

"We are not willing to discuss a UN presence in Sri Lanka for monitoring purposes nor are we willing to allow an office of the High Commissioner (here)," Human Rights minister Mahinda Samarasinghe said in October after a visit of UN High Commissioner for Human Rights Louise Arbour.