Seven persons had been arrested in connection with the blasts.
A string of eight devastating blasts, including suicide attacks, struck churches and luxury hotels frequented by foreigners in Sri Lanka on Easter Sunday, killing 215 people and shattering a decade of peace in the island nation since the end of the brutal civil war with the Liberation Tigers of Tamil Eelam.
The blasts -- one of the deadliest attacks in the country's history -- targeted St Anthony's Church in Colombo, St Sebastian's Church in the western coastal town of Negombo and Zion Church in the eastern town of Batticaloa around 8.45 am (local time) as the Easter Sunday mass were in progress, police spokesman Ruwan Gunasekera said.
Explosions were reported from three five-star hotels -- the Shangri-La, the Cinnamon Grand and the Kingsbury in Colombo.
Gunasekera confirmed 207 deaths. However, the News 1st channel said that 215 people have died in the blasts.
Director of the National Hospital Dr Anil Jasinghe identified 11 of the 27 foreign nationals killed in the coordinated attacks believed to be carried out by a single group.
An Indian, two Chinese and one each from Poland, Denmark, Japan, Pakistan, America, Morocco and Bangladesh are among the dead at the National Hospital.
Around 500 people, including Indians, were injured in the attacks.
No group has claimed responsibility for Sunday's attacks.
However, most of the deadly attacks in the past in Sri Lanka were carried out by the LTTE, which ran a military campaign for a separate Tamil homeland in the northern and eastern provinces of the island nation for nearly 30 years before its collapse in 2009 after the Sri Lankan Army killed its supreme leader Velupillai Prabhakaran.
Briefing reporters, Gunasekera said the police was not able to confirm at the moment if they were all suicide attacks. He, however, said that one of the blasts at the Katuwapitiya (Negombo) church has signs of being what looked like a suicide attack.
An unnamed official said a suicide bomber blew himself up at the restaurant of the Cinnamon Grand hotel.
Gunasekara said that 66 bodies were kept at the National Hospital while 260 injured were receiving treatment there and 104 bodies were placed at the Negombo Hospital and 100 injured were receiving treatment at the Hospital.
Later in the day, a powerful blast in the capital's southern suburb near the Colombo Zoo killed two persons, Gunasekera said.
When a police team entered a house in the Colombo north suburb of Orugodawatta to conduct a search, a suicide bomber blew himself up causing a concrete floor of a two-storey building to crash on them, killing three policemen in the eighth blast, police said.
Soon after the eighth blast, the government imposed curfew with immediate effect. The curfew will be in force indefinitely until further notice, officials said.
State Minister of Defence Ruwan Wijewardene said seven persons had been arrested in connection with the blasts.
"We believe these were coordinated attacks, and one group was behind them," Wijewardene said.
Lankan President Maithripala Sirisena has appealed for calm. "I have been shocked by this totally unexpected incidents. The security forces have been asked to take all action necessary," Sirisena said.
Lanka’s Prime Minister Ranil Wickremesinghe termed the blasts as "cowardly attacks" and said his government was working to "contain the situation."
"I call upon all Sri Lankans during this tragic time to remain united and strong... The government is taking immediate steps to contain this situation," he tweeted.
Security has been intensified around the religious places across the capital. The government has temporarily blocked all social media platforms.
"Horrible scenes. I saw many body parts strewn all over," said Harsha de Silva, Sri Lanka's Minister of Economic Reforms and Public Distribution.
The Indian High Commission in Colombo said that it was closely monitoring the situation in Sri Lanka.
"We are closely monitoring the situation. Indian citizens in need of assistance or help and for seeking clarification may call the following numbers : +94777903082 +94112422788 +94112422789," the High Commission tweeted.
"In addition to the numbers given, Indian citizens in need of assistance or help and for seeking clarification may also call the following numbers +94777902082 +94772234176," it said.
The first blasts were reported at St Anthony's church in Colombo and St Sebastian's Church in Negombo just outside the capital.
"A bomb attack to our church, please come and help if your family members are there," read a post in English on the Facebook page of the St Sebastian's Church.
Images circulated on social media showed severely damaged St Sebastian's church, with a shattered ceiling and blood on the pews.
Heavy security has been deployed at the Bandaranaike International Airport. The riot police and the Special Task Force, extra police security has been deployed around the airport, state-run Daily News reported.
Leave of all police personnel has been cancelled in the wake of blasts.
Doctors, nurses and health officials who were on leave have been asked to report to work, Health Ministry sources said.
All state Universities have been closed until further notice.
Cardinal Malcolm Ranjith said all Easter masses in the Colombo District have been cancelled.
Former president Mahinda Rajapaksa, under whose leadership the Lankan Army crushed the LTTE, termed the attack as "barbaric".
"We will not tolerate such violence, such acts of terrorism, of cowardice within our borders once again," he said.