UN experts have urged the Government of Sri Lanka to ensure, without further delay, truth, justice and reparation for the families of the humanitarian workers killed 20 years ago in the town of Muttur.
On 4 August 2006, amid intensifying hostilities between the Sri Lankan Army and the Liberation Tigers of Tamil Eelam (LTTE), 17 national Action Against Hunger (ACF) humanitarian workers were found executed at their compound in Muttur, most of them with gunshot wounds to the head. ACF was the only international NGO still providing water, sanitation and hygiene services to the local population at the time.
“The victims were not combatants. They were humanitarian workers providing life-saving assistance to civilians caught in armed conflict,” the UN experts said in a statement.
“Their killing was not only a devastating attack on humanitarian personnel but also undermined the delivery of essential assistance to conflict-affected communities.”
The experts recalled that successive international investigations concluded that there are reasonable grounds to believe members of Sri Lanka’s security forces were responsible for the killings, including the OHCHR Investigation on Sri Lanka (OISL) published in 2015. Yet domestic commissions of inquiry were marred by evidentiary failures, inadequate witness protection and political interference, including the 2008 withdrawal of the International Independent Group of Eminent Persons (IIGEP) overseeing the process, which cited a “lack of political will” to pursue accountability.
“Nearly 20 years later, those responsible have still not been arrested, prosecuted or punished,” the experts said. “This enduring impunity has prolonged the suffering of victims’ families and undermined confidence in the rule of law.”
“Accountability is essential not only to honour the memory of those who were killed, but also to reaffirm that attacks against humanitarian personnel will never be tolerated and must never go unpunished,” they said.
The experts stressed that the killing of ACF staff had direct and foreseeable consequences for the human rights of the more than 325,000 highly vulnerable displaced people in the area. Disruption to well rehabilitation programmes, the Kantalai water treatment plant, food distribution and agricultural support increased the population’s exposure to unsafe drinking water, malnutrition and water-borne diseases at a time when humanitarian aid was indispensable for their survival.
“The victims’ families have endured two decades of waiting, threats and displacement, without answers or effective remedy. Their suffering may amount to cruel, inhuman or degrading treatment in itself,” the experts said.
The massacre also had wider chilling effect on humanitarian action in Sri Lanka with more than 2,000 aid workers leaving the northern and eastern provinces in the months following the attack and continued shrinking humanitarian space until the end of the conflict in 2009.
“Impunity for attacks on humanitarian personnel sends a devastating message. 2025 was the deadliest year on record for aid workers worldwide, with over 1,000 killed between 2023 and 2025. We cannot allow a lack of accountability in cases like Muttur to keep fuelling this trend,” the experts said.
“We urge the Government of Sri Lanka to immediately open, or reactivate, a prompt, independent, impartial and effective investigation into the Muttur massacre, provide comprehensive reparation to the victims’ families, and guarantee the protection of all those wishing to mark the 20th anniversary.”
The experts are in contact with the Government of Sri Lanka on this matter, the statement said.
