Chilling footage shows suspected Sri Lanka bomber patting child before detonating bomb

Chilling new footage shows one of the suspected Sri Lankan terrorists stopping to pat a young girl on the head, before walking into a church and detonating his explosives.

The CCTV footage shows the alleged bomber carrying a large backpack and walking towards the St Sebastian's Church before meeting the small child. Afterwards he enters the church by a side door and carries out the attack.

"At the end of the mass [my family] saw one young man go into the church in with a heavy bag," witness Dilip Fernando told media.

"He touched my granddaughter's head on the way past. It was the bomber."

"What we have seen from the CCTV footage is that all the suicide bombers were carrying very heavy backpacks. These appear to be crude devices made locally," a source told the Daily Mail.

The Sri Lankan Government says he was one of at least seven suicide bombers who carried out the horrific attacks, which killed at least 320 people.

The first explosion hit St Anthony's Church around 8:45am on Sunday (local time) as the Easter Mass took place, according to local journalist Roel Raymond.

Minutes later, another explosion ripped through St Sebastian's Church and the Zion Evangelical Church in Batticaloa, before three hotels were reportedly attacked - the Kingsbury Hotel, Shangri-la Hotel and Cinnamon Grand Hotel in Colombo.

Another video released by Islamic State (IS) appears to show the terrorists who carried out the attacks pledging their allegiance to IS.Their leader is believed to be National Thowfeek Jamaath leader Moulvi Zahran Hashim.

At a news conference on Tuesday night, Sri Lanka Prime Minister Ranil Wickremesinghe warned there were more militants and explosives "out there" and officials would follow up the IS's claims.

"We will be following up on Isis's claims, we believe there may be links," he said.