Scores of people killed after multiple blasts at churches and hotels in Sri Lanka

Scores of people have died in Sri Lanka after six bombs detonated near simultaneously at three churches and three luxury hotels popular with tourists, authorities say.

At least 138 people have been killed and 400 more injured in the Easter Sunday bombings about 8.45am (local time), hospital and police officials have said.

The strikes came as worshippers were attending Easter Sunday services at Catholic churches. The first explosion reportedly struck at a church in Colombo, followed by simultaneous blasts within half an hour, according to Al Jazeera.

In just one church, St Sebastian's in Katuwapitiya, north of Colombo, more than 50 people had been killed, a police official told Reuters, with pictures showing bodies on the ground, blood on the pews and a destroyed roof.

Media reported 25 people were also killed in an attack on a church in Batticaloa in Eastern Province.

The injured also included foreigners staying at the three five-star hotels - the Cinnamon Grand, Kingsbury and the Shangri-La, located in the heart of Colombo.

It was unclear whether there were any casualties in the hotels, however, nine foreigners were among the dead, the officials said.

A spokesman for the Cinnamon Grand Hotel near the prime minister's official residence in Colombo, told AFP that the blast had ripped through the hotel restaurant.

He said at least one person had been killed in the blast.

St Sebastian's Church in Negombo, a Catholic majority town, posted pictures of destruction inside the church on its Facebook page, showing blood on pews and the floor, and requested help from the public.

"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.

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.

Police spokesman Ruwan Gunasekera said that the injured were being evacuated while security forces have cordoned off the areas and search operations are underway.