The United Nations on Sunday urged Sri Lanka to bridge its “accountability deficit” and ensure justice as the country commemorated the 279 victims of its worst-ever attack against civilians five years ago.

The UN’s top envoy to the country, Marc-Andre Franche, told a remembrance service in Colombo that there should be a “thorough and transparent investigation” to uncover those behind the Easter carnage in 2019.

Islamist bombers hit three churches and three hotels in the island’s deadliest suicide attack aimed at civilians, but grieving families say they are still waiting for justice.

Among the dead were 45 foreigners, including tourists visiting the island a decade after the end of a brutal ethnic conflict that had claimed more than 100,000 lives since 1972.