Image copyright ACF Image caption ACF published photos of the victims

A French charity has accused Sri Lanka's security forces of killing 17 of its aid workers in 2006, and demanded an international inquiry.

Action Against Hunger (ACF) said it had been awaiting the outcome of Sri Lanka's own inquiries but they had turned into a "farce".

The workers were found shot dead at their office in the town of Muttur.

A Sri Lankan military spokesman rejected ACF's allegations, suggesting the charity had withheld evidence.

ACF said its workers had been lined up, forced to kneel and each shot in the head.

The killings happened as security forces took control of Muttur, while fighting Tamil Tiger rebels.

Other allegations of war crimes overshadowed a Commonwealth summit held in Sri Lanka this month.

Names and photos

Human rights activists have previously accused Sri Lanka's security forces of the killings but ACF said it had held off, awaiting the official version of events.

It then 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".

According to ACF's report, all of the alleged victims were Tamils. They are listed by name, along with their photographs.

ACF said it had lost contact with its mission in Muttur at around 7am on 4 August 2006, as fighting raged around it.

A few days later, the 17 staff members were found dead.

"Lined up inside the ACF compound, they had been shot dead at close range...," the report says.

"Staying away from direct hostilities, ACF staff were not killed by stray bullets. They were deliberately targeted, despite the fact that they were wearing white ACF T-shirts and were not armed."

Soldiers and police then attempted to block any investigation into the deaths, according to the charity's report.

Army denial

The charity said it was not giving the names of the killers as the report was not meant to replace a judicial inquiry.

Sri Lankan military spokesman Brig Ruwan Wanigasooriya said that withholding alleged evidence instead of releasing it in support of the government's investigation raised suspicion about the group's motives.

"This is another instance of a pattern which has emerged since the end of the conflict where certain organisations level allegations against the government without providing sufficient details to enable an investigation," he said.

The full death toll from the country's civil war, which ended after 26 years in 2009 with a government victory, is unknown.

Some 70,000 people had been killed by the time the conflict entered its furious final months, when the UN believes that tens of thousands may have died.