The Islamic State terrorist group on Tuesday claimed responsibility for the bomb blasts that left 321 people dead and over 500 wounded in Sri Lanka on Sunday. The outfit made the claim through its Amaq news agency, Reuters reported.

Meanwhile, all police stations in Colombo have been advised to stay on high alert based on reports of an explosive-laden van entering the city, Daily Mirror reported. The Director of Security at the Colombo harbour said intelligence agencies had found that an unidentified container truck and a van carrying a likely explosive device was heading towards Colombo.

Search operations are under way at Colombo harbour, PTI reported.

Sri Lanka’s State Minister of Defence Ruwan Wijewardene on Tuesday told Parliament that investigations showed the bombings were retaliation for the Christchurch attacks last month.

As many as 50 people were killed in the shootings at mosques in Christchurch, New Zealand on March 15.

Wijewardene also said that the toll in the blasts in Sri Lanka had risen to 321. He said 38 of the deceased were foreigners. At least 10 Indians also died in the attacks. Sri Lanka had declared a state of emergency on Monday.