Death toll in Sri Lanka bomb attacks rises to 310
Around 500 people were wounded in the blasts, Ruwan Gunasekera said in a statement.
He added that 40 people were now under arrest in connection with the attacks.
Eight co-ordinated explosions targeted Easter worshippers and high-end hotels popular with international guests.
Sri Lanka's small Christian minority — just six per cent of the 21 million-strong population — has been targeted by violence in the past, but never to such brutal effect.
At least two of the explosions involved suicide bombers, including one who lined up at a hotel breakfast buffet before unleashing carnage.
Tensions remained high and security heavy after a bomb discovered by police on Monday near one of the targeted churches blew up before police could defuse it. Although there was a powerful blast, no injuries were reported.
Police also found 87 bomb detonators at a Colombo bus station.
Details have begun to emerge about some of the foreigners killed in the blasts.
The United States reported at least four Americans killed — including a child — and the Netherlands raised their toll to three.
A Danish billionaire lost three of his children in the attacks, a spokesman for his company said.
Eight Britons, eight Indians and nationals from Turkey, Australia, France, Japan and Portugal, were also killed, according to Sri Lankan officials and foreign governments.
The suicide bombers hit three Colombo luxury hotels popular with foreign tourists — the Cinnamon Grand, the Shangri-La and the Kingsbury — and three churches: two in the Colombo region and one in the eastern city of Batticaloa.
Two additional blasts were triggered as security forces carried out raids searching for suspects.
Interpol said it was deploying investigators and specialists to Sri Lanka, and the US State Department warned of possible further attacks in a travel advisory.
Sri Lankans woke to emergency law on Tuesday as authorities searched for those behind suicide bomb attacks on churches and luxury hotels.
The president’s office declared that emergency law would come into effect from midnight, giving police extensive powers to detain and interrogate suspects without court orders. An overnight curfew was also put into effect.
Tuesday was also declared a national day of mourning.
The Washington Post quoted an unidentified law enforcement official as saying Federal Bureau of Investigation (FBI) agents were being sent to Sri Lanka to assist in the investigation.
The FBI has also offered laboratory expertise to test evidence and analysts were scouring databases for information that might shed light on tea attacks, the Post said.