Watch: The Moment A Suicide Bomber Entered The Church In Sri Lanka And Blew Himself Up Killings Hundreds

Footage has emerged showing one of the suspected bombers behind Sunday's blasts in Sri Lanka, in which more than 300 people died. Sri Lanka has held its first mass funeral amid a day of mourning for the victims of Sunday's bomb blasts. The death toll from the attacks on churches and hotels has risen to 321 with about 500 wounded, police said. A state of emergency is in effect to prevent further attacks. The Islamic State (IS) group claimed the attack on Tuesday via its news outlet. Sri Lanka's government has blamed the blasts on local Islamist group National Thowheed Jamath (NTJ). The country's prime minister, Ranil Wickremesinghe, said the government believed there "may be links" to IS. "This could not have been done just locally," he said. "There had been training given and a coordination which we are not seeing earlier." A BBC correspondent in Sri Lanka says the IS statement should be treated cautiously. As with previous attacks that the group says it carried out, it has provided no evidence for the claim. ALSO READ: Sri Lanka Bombings: Photos, videos and all you need to know Video The Moment A Suicide Bomber Entered The Church In Sri Lanka And Blew Himself Up Killings Hundreds from Cyprian, Is Nyakundi on Vimeo .