http://www.adaderana.lk/news/54693/1...sainthamaruthu

15 bodies including children found at blast site in Sainthamaruthu

The 3-minute video is worth viewing. A slain police officer previously owned one of the rifles recovered. The explosives and denotators looked to me like the type used by construction companies. It is probably that the Sri Lankan security forces may be right, and may not have involved external assistance.

However, the following certainly indicates ISIS-inspired.

Meanwhile, during another search operation carried out last evening (26) in Samanthurai area, Army troops recovered ISIS flags, literature and some other objects from a place, said to be the terrorist organization’s place for oath-taking.

According to the Military Spokesman, Brigadier Sumith Atapattu, combined troops recovered explosives, detonators, gelignite sticks, acid bottles, det cords, ISIS flags and backdrop, suicide kits, military uniforms, etc from a safe house in Samanthurai area.
https://edition.cnn.com/2019/04/26/a...ntl/index.html

Sri Lanka bombers' mentor is dead, but his memory still stokes fear

Zahran Hashim had preached hate and violence for years. On Easter Sunday, at the Shangri-La hotel in Colombo, he put those words into action.

As guests took breakfast in a cafe overlooking the sea, Zahran blew himself up, Sri Lankan officials say. If a later video released by an ISIS-affiliated news agency is to be believed, Zahran was the leading figure in a band of suicide bombers which tore apart hotels and churches across the country that morning.
Not surprisingly, reporters have a better understanding of the situation than so-called U.S. security and intelligence experts. I asked some recently if there were different sects of Islam in Sri Lanka and received a simpleton answer that was basically no. Zahran not only defaced Buddhist sites, but he also harassed and threatened Sufis before the attack. The Sri Lankan government dropped the ball but arguably so did Western intelligence services.

Extremists consider Sufis to be kafir, or unbelievers, and in one video on YouTube, Zahran said that if someone "is a kafir he is to be killed according to Sharia law." In Kattankudy, local Sufis ticked off a litany of harassment and violence in recent years, including bullets fired at the mosque offices and a 2017 attack by Zahran and a mob of followers wielding swords.