The death toll from a devastating series of eight bomb blasts that ripped through high-end hotels and churches holding Easter services in Sri Lanka on Sunday has risen to 207, police spokesman Ruwan Gunasekera said. At least 450 people were injured in the attacks.

At least two of the eight attacks were carried out by suicide bombers, according to police and other sources, and three police were killed when another suicide bomber detonated explosives during a raid on a house where suspects were. At least 13 suspects have been arrested in connection with the attacks.

Police spokesperson Ruwan Gunasekera said the police were investigating whether suicide bombers were involved in all of the blasts.

The government said earlier that investigators would look into whether the attackers had "overseas links."

There were no immediate claims of responsibility for the attacks in a country which was at war for decades with Tamil separatists until 2009 during which bomb blasts in the capital were common.

Christian groups say they have faced increasing intimidation from some extremist Buddhist monks in recent years. And last year, there were clashes between the majority Sinhalese Buddhist community and minority Muslims.

At a glance:

• Four hotels ─ Cinnamon Grand, Shangri-La, Kingsbury and Tropical Inn ─ targeted in Colombo
• One church each targeted in Colombo (St Anthony's Shrine), Negombo (St Sebastian's Church) and Batticaloa (Zeon Church)
• At least 47 killed in Colombo blasts: police
• At least 25 killed in Batticaloa blast: police
• At least 67 killed in Negombo blast: police
• 35 foreigners ─ including Dutch, US and UK citizens ─ dead: police
• At least 450 injured
• Curfew, 'temporary' social media ban imposed

Trail of terror

Three churches ─ one each in Colombo, Negombo and Batticaloa ─ and three Colombo hotels were targeted in the initial series of blasts. Another hotel and an unspecified location in Colombo were struck by two more blasts two hours later.

The death toll included worshippers and hotel guests. The injured flooded into local hospitals, where officials reported hundreds of wounded were being admitted.

Hospital sources said British, Dutch and American citizens were among the dead, with Britons and Japanese also injured. A Portuguese man also died, the country's LUSA news agency reported. Four Pakistanis were among the injured, according to the Foreign Ministry.

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The first explosions were reported at St Anthony's Church in Colombo and St Sebastian's Church in the town of Negombo just outside the capital.

Shortly after those blasts were reported, police confirmed three hotels in the capital had also been hit, along with a church in the town of Batticalao, in the east of the country. Police immediately sealed off the attack sites. Sri Lankan security officials are investigating the attacks.

A person identified as Alex Agieleson who was near St Anthony's at the time said that nearby buildings shook with the impact of the blast, and that he saw a number of injured people being carried away in ambulances.

An AFP photographer at the scene at St Anthony's saw bodies lying on the floor, some draped with scarves and clothes.

Much of the church roof was blown out in the explosion, with roof tiles, glass and splintered wood littering the floor along with pools of blood.

St Sebastian's appealed for help on its Facebook page. The explosion ripped off the roof and knocked out doors and windows at the church, where people carried the wounded away from blood-stained pews, TV footage showed.

Local TV showed damage at the Cinnamon Grand, Shangri-La and Kingsbury hotels in the capital. The Shangri-La's second-floor restaurant was gutted in the blast, with the ceiling and windows blown out. Loose wires hung and tables were overturned in the blackened space.

A police magistrate was at the hotel to inspect the bodies recovered from the restaurant. From outside the police cordon, several bodies could be seen covered in white sheets.

A manager at the Cinnamon Grand, near the prime minister's official residence in Colombo, said a suicide bomber blew himself up at the hotel's restaurant.

“He came up to the top of the queue and set off the blast,” he told AFP.

Photos circulating on social media showed the roof of one church had been almost blown off in the blast. The floor was littered with a mixture of roof tiles, splintered wood and blood. Several people could be seen covered in blood, with some trying to help those with more serious injuries. The images could not immediately be verified.

Hours after the first series of blasts, a seventh blast struck at a hotel in Colombo's Dehiwala area and killed two people, police spokesperson Ruwan Gunasekera said.

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"There was an explosion in a hotel in Dehiwala near the zoo," a police official told Reuters adding that there were no further details available. An eyewitness on local TV said he saw some body parts including a severed head lying on the ground near the hotel. Zoo officials declared Dehiwala zoo closed after the blast.

Shortly after, an eighth blast hit the suburb of Orugodawatta in the north of Colombo, police said, without providing additional details on what was targeted.

A suicide bomber also killed three police officers as they raided a house in a northern suburb of the city.

After the eighth explosion, the government declared a curfew with immediate effect and said it would last "until further notice".

A social media ban was also imposed across the country. Government officials said major social media networks and messaging apps, including Facebook and WhatsApp, have been blocked to prevent misinformation and rumours.

Police chief warned of threat 10 days ago

According to a document accessed by AFP, the Sri Lankan police chief had warned of possible suicide attacks targeting "prominent churches" in a nationwide alert 10 days ago.

Police chief Pujuth Jayasundara sent an intelligence warning to top officers on April 11 setting out the threat.

"A foreign intelligence agency has reported that the National Thowheed Jama'ath (NTJ) is planning to carry out suicide attacks targeting prominent churches as well as the Indian High Commission in Colombo," said the alert. The NTJ came to notice last year when it was linked to the vandalisation of Buddhist statues.

SL PM calls emergency meeting

Sri Lankan Prime Minister Ranil Wickremesinghe condemned the attacks and called an emergency security council meeting, sources told Reuters.

"I strongly condemn the cowardly attacks on our people today. I call upon all Sri Lankans during this tragic time to remain united and strong," Wickremesinghe said in a Tweet. "Please avoid propagating unverified reports and speculation. The government is taking immediate steps to contain this situation."

Minister of Economic Reforms and Public Distribution, Harsha de Silva, tweeted: "Emergency meeting called in a few minutes. Rescue operations underway."

He said he had been to two of the attacked hotels and was at the scene at St Anthony's Shrine, where he described "horrible scenes".

"I saw many body parts strewn all over," he tweeted, adding that there were "many casualties including foreigners".

"Please stay calm and indoors," he added.

President Maithripala Sirisena, in an address following the attacks, said he was shocked by the explosions and appealed for calm.

Finance Minister Mangala Samaraweera, writing on his verified Twitter account, said the attacks had killed "many innocent people" and appeared to be a "well-coordinated attempt to create murder, mayhem and anarchy."

The Pakistani Foreign Office retweeted contact information for the Pakistani High Commission in Colombo for Pakistani nationals in Sri Lanka.

Embassies in Colombo warned their citizens to shelter in place, and Sri Lankan Airlines told customers to arrive at the airport four hours ahead of flights because of ramped-up security in the wake of the attacks.

SL Christians targeted by discrimination, violence

Only a small fraction of mainly Buddhist Sri Lanka is Catholic, but the religion is seen as a unifying force because it includes people from both the Tamil and majority Sinhalese ethnic groups.

Last year, there were 86 verified incidents of discrimination, threats and violence against Christians, according to the National Christian Evangelical Alliance of Sri Lanka (NCEASL), which represents more than 200 churches and other Christian organisations.

This year, the NCEASL recorded 26 such incidents, including one in which Buddhist monks allegedly attempted to disrupt a Sunday worship service, with the last one reported on March 25.

Out of Sri Lanka's total population of around 22 million, 70pc are Buddhist, 12.6pc Hindu, 9.7pc Muslim, and 7.6pc Christian, according to the country's 2012 census.

In its 2018 report on Sri Lanka's human rights, the US State Department noted that some Christian groups and churches reported they had been pressured to end worship activities after authorities classified them as "unauthorised gatherings".

The Catholic Church in the Holy Land voiced support for Sri Lanka's Christians and condemned the attacks. A statement issued in Jerusalem said the blasts were particularly sad as they "came while Christians celebrate Easter."

"We pray for the souls of the victims and ask for speedy recovery of the injured, and ask God to inspire the terrorists to repent of their killing and intimidation," the statement said.

"We also express our solidarity with Sri Lanka and all its inhabitants in their various religious and ethnic backgrounds."