Roland Buerk BBC Colombo correspondent

Twenty police officers and soldiers are among more than four hundred people detained since September under wide ranging public security laws.

The statement comes as the Government is defending its human rights record.

The numbers of abductions and killings have been increasing in Sri Lanka as the country has slid back towards a civil war.

The Human Rights Commission says it received reports of more than a hundred and fifty cases last month alone.

On Tuesday the bodies of five men were found in the north of the country, on Saturday five more were discovered in a swamp near the capital Colombo.

The police have launched a crack down, arresting more than four hundred and fifty people since September under wide a ranging public security ordinance.

Among them are five police officers and fifteen soldiers. "Out of the arrests of the defence personnel, some may be involved in abductions and killings and disappearances," said Keheliya Rambukwela, a minister and the Government's defence spokesman.

He said that it would be some time before charges were brought. The announcement comes as Sri Lanka's Government comes under pressure over its human rights record.

It will be discussed at a meeting of the United Nations Human Rights Council next week.

A UN envoy Allan Rock has alleged that some security forces personnel turned a blind eye to the recruitment of children by the Karuna Group, a breakaway faction from the Tiger rebels.

The Government has denied it. Campaign groups are now calling for an international human rights monitoring mission to be sent to Sri Lanka.