When the Tamil Tiger rebels ran a de facto state here, the Jaffna peninsula boasted the best maintained ``martyrs' graves'' where hundreds of young men and women killed fighting government troops were buried and honoured.The Kopay cemetery dedicated to 988 Tiger men and women has long been bulldozed after government troops wrested control of this Tamil heartland in December 1995.

But skeletons are now emerging from other graves. Forensic experts dug out two skeletons at a suspected mass grave pointed by a government soldier who claims he was asked to dispose of suspected Tamil rebels killed by his superior officers during 1996.

American forensic expert William Haglund of the Physicians for Human Rights Organisation said he believed Sri Lanka was the only country to allow a grave inquiry at a time when government forceswere still fighting rebels.``We are encouraged by the process... it is good that they have not rushed into it because that could perpetuate a crime by destroying the evidence,'' Haglund said as the painstaking excavations got underway on Wednesday. Even before the experts unearthed human remains from a site believed to have some 400 bodies of people allegedly killed by government forces, municipal labourers accidentally stumbled on 21 skeletons at a stadium here.

The find of skeletons in April at the Duraiappa Stadium is also under investigation, Jaffna's top police officer, Nimal Mediwaka said amid fears that the victims may have been killed more than 10 years ago.

The region was then run by Indian troops sent to Sri Lanka's northeast in accordance with a bilateral peace pact which sought to end the island's drawn out Tamil separatist conflict that has now claimed more than 55,000 lives.

The Indian troops known as the Indian Peace Keeping Force (IPKF) ended up fighting the separatist Liberation Tigersof Tamil Eelam who refused to accept the Indo-Sri Lanka peace pact, which had been honoured by other Tamil groups. The latest probe at the suspected mass grave in Chemmani, 11 km south of here, could seriously embarrass the military and the stadium skeletons may reopen old wounds and rekindle memories of the IPKF.The forensic excavations carried out under international supervision were partly triggered by pressure from human rights groups as well as the government's desire to wipe its rights record clean amid mounting criticism.What has baffled foreign rights groups and diplomats has been the attitude of Tamil Tiger guerrillas to the investigation. Lawyers said magistrates hearing the mass grave case had withdrawn following fears that the rebels may target them. The case is currently being heard by the fourth magistrate assigned to it. One judge lasted only two days on the case.

Tamil residents here believe the Tigers may be fearing the probe could be extended beyond 1995 when the Tigers ran a de factostate here. The Tigers have been accused of killing hundreds of rival Tamils.

Ingrid Massage, the representative of the London-based rights group, Amnesty International, said some members of Sri Lankan security forces were also clearly unhappy about the excavations.

However, Jaffna Security Forces commander Lohan Gunawardena said: ``We have come so far in this (inquiry) let us see where it goes.''

Asked if the inquiry could affect troops morale, he said: ``This is a convicted man saying various things. So let us see.'' He was referring to former soldier and convicted rapist and murderer Somaratne Rajapakse, who implicated his superiors and pointed to the site military police were deployed to ensure ordinary soldiers did not have access to Rajapakse during his stay at the prison here.

Massage said she also believed there were many in the government forces who were keen to see that ``high human rights standards'' were established in the military. Rights organisations have reported that 600 people whodisappeared during 1996 here may have been killed after being arrested by government forces.

However, they say there have been no significant disappearances since mid-1997.But the latest digging has come back to haunt the military -- and worry its foes.