New York, Aug 2 (IANS): Sri Lankan authorities have failed to bring to justice those responsible for the execution-style killing of 17 aid workers 13 years ago, Human Right Watch said on Friday.

On August 4, 2006, alleged Sri Lankan security forces murdered local staff members from the Paris-based Action Contre La Faim (Action Against Hunger, ACF) at their compound in the town of Muttur in the eastern district of Trincomalee.

On June 13, 2019, Sri Lanka's Attorney General Dappula de Livera ordered police to speed up investigations into the ACF massacre as well as the murder of newspaper editor Lasantha Wickrematunge on January 8, 2009 and two other high-profile criminal cases.

De Livera said that he was singling out the four cases because delays had caused public distress. He ordered the acting police chief to report on the progress.

"Thirteen years have not brought the Sri Lankan Police any closer to bringing to justice those responsible for the summary execution of 17 aid workers," said Human Rights Watch.

"The ACF case shows the need for the government to seek international judicial assistance to prosecute these and other killings."

The killings of the ACF workers - 16 Tamils, including 4 women, and a Muslim - occurred after several days of fighting between government forces and the separatist Liberation Tigers of Tamil Eelam (LTTE) for control of Muttur.

The ACF team had been providing assistance to survivors of the December 2004 Indian Ocean tsunami. The civil war ended in May 2009, with the LTTE's military defeat.