Colombo, Feb 25 (IANS): Over 80 human bones, including skeletal remains, have been found so far from a mass grave in northern Sri Lanka, police of this island nation said Tuesday.

Excavation work was carried out at the grave site in the northern Mannar town after the grave was first discovered in December last year, Xinhua reported.

The police said that 11 human remains were found Monday when excavation was carried out at the location, which was once under the control of Sri Lankan rebels.

The police said the remains were yet to be identified and they have been sent for further investigations.

The criminal investigations department is investigating the discovery and there is a suspicion the remains may be of people killed by the Tamil Tigers during the war.

Most parts of Sri Lanka's Tamil-dominated north were under rebel control for the most part of 30 years before the rebels were defeated in May 2009.

A UN panel and human rights groups had accused the Sri Lankan military and Tamil Tigers of committing war crimes during the final stages of the war.

The Northern Provincial Council recently called for a UN-backed investigation into the mass grave in Mannar, but the government has refused to consider such a request.

Meanwhile, the police are also investigating another mass grave in central Sri Lanka where over 150 skeletal remains and bones were unearthed last year.

The mass grave in Matale was discovered by construction workers.