Updated

A French aid group accused Sri Lankan security forces on Tuesday of executing 17 of its local employees in 2006 during the country's civil war, and said the government has protected the killers.

Action Against Hunger said in a statement that it has information implicating the army, navy and police personnel. It said they lined up the victims at their office in the eastern town of Muttur, forced them to their knees and shot them in their heads.

The group said its information came from witnesses, confidential documents and diplomatic contacts.

The victims had been trapped in their office amid heavy fighting between government forces and Tamil Tiger rebels in August 2006. Their bodies were recovered several days later.

The organization said its position previously had been to await the outcome of a local investigation, but decided to publicly denounce the perpetrators because "relevant domestic mechanisms have been exhausted, witnesses have been silenced and the internal Sri Lankan investigation has become a farce. “

It asked for an international investigation into the massacre.

Military spokesman Brig. Ruwan Wanigasooriya said the government "remains committed to conduct impartial and comprehensive criminal investigations and domestic inquiries into any complaints and information received, relating to alleged perpetration of crimes by members of the armed forces and the police."

The government earlier accused the rebels of killing the aid workers and the aid group's headquarters of exposing them to danger. There has been no proper government investigation, and families do not speak up, fearing reprisals.

Sri Lankan forces and the now defeated Tamil Tiger rebels, who fought for an independent state for ethnic minority Tamils, are accused of serious human rights violations and possible war crimes during the quarter-century civil war, which ended in 2009.

The country has so far ignored calls for a thorough local inquiry into war abuses and says it will not allow any international probe.