A major reshuffle in Sri Lanka's government, just days after the Easter Sunday bombings. The president says he's replacing the heads of the defense agencies for failing to act on warnings they received two weeks before the attacks. More than 300 people were killed in 8 coordinated bombings at churches and hotels. At least 45 were children. ISIL has claimed responsibility. 58 suspects have been arrested. But the government warns there might be more militants at-large armed with explosives. CGTN's Ravinder Bawa has more on the investigation in a country that has plunged into grief.

On the national day of mourning, relatives of those who were killed in explosions in Negombo church gathered to offer their last homage.

Many attended the funeral service of the first mass burial amidst prayers and grief.

RAVINDER BAWA COLOMBO "It is in this St Sebastian's church in Kattuapetiya that 110 people died and fifteen are still struggling for their lives in hospitals. There is an eerie silence in the village, lets find out what's on the minds of the people."

FATHER RIDELY PARISH PREIST NEGOMBO "Eventually we must find out those people who attacked the church and government should take action against them."

ASANTHI FERNANDO SCHOOL TEACHER "We don't want to hear more devastating things like this and we want safety. The government should take more actions."

One of the local channels showed the alleged suicide bomber entering the church minutes before the explosion. The government strongly suspects the hand of Islamic State, which was soon confirmed by the organization on Twitter, but provided no evidence.

RANIL WICKREMESINGHE SRI LANKAN PRIME MINISTER "We certainly the security apparatus are of the view there are foreign links and some of the evidence points to that. So if the IS (Islamic State) claimed it, we will be following up on this claim. There was suspicion of links with ISIS."

While the Lankan authorities recover from their security lapse, the FBI has agreed to assist in its investigation.

A state of emergency is still in effect and Sri Lanka is on edge.

But on Tuesday, the country plunged into mourning.

Ravinder Bawa, Colombo.