Colombo : Civilian volunteers cleared debris and assisted the wounded in the northern coastal strip of Sri Lanka, where at least 400 people were killed and more than 1,200 injured from combat between government troops and Tamil rebels, a doctor in the rebel-held area said Monday.

Medical doctor Veerachchami Shanmuagaraja told the German Press Agency dpa by phone that more injured people had been brought to a makeshift hospital set up in the Mullivaikal junior school, 392 kilometres north-east of the capital.

He said there were women and children the dead and wounded, and that he was unable to provide proper treatment for lack of medicines and supplies.

"The fighting ceased in the morning hours and people are moving away further towards the beach," the doctor said.

An earlier Tamil rebel statement claimed that more than 2,000 civilians were killed due to shelling by the army Sunday in an area demarcated as a "safety zone."

The Defence Ministry said the rebels had fired mortars targeting civilians in the safety zone Sunday, causing the casualties.

"It is believed that scores of civilians were killed while many others sustained injuries due to the deliberate attack launched by the terrorists to gain media mileage against government forces," the ministry said.

It was not possible to independently confirm the claims made by the government or the rebel Liberation Tigers of Tamil Eelam from the area where journalists have no access to.

An estimated 20,000 civilians are trapped in the last rebel held area which extends to about six square kilometers according to the government, but UN agencies estimate that there are around 50,000 civilians.

The military says it is in the final phase of a major operation to crush the rebels, who have been fighting for an independent homeland for minority Tamils in the north and eastern parts of the country for the last 25 years.