More than 200 people have been killed and 450 injured in a string of bomb attacks on hotels and churches as worshippers attended Easter services.
Americans, British and Dutch citizens were among dozens of foreigners killed.
At least seven blasts were reported, four at hotels and three at churches.
The first attacks took place at St Anthony’s Church in Colombo and St Sebastian’s Church in the town of Negombo, just outside the capital.
Shortly afterwards police confirmed three hotels in the capital – the Shangri-La, Cinnamon Grand and Kingsbury – had also been hit, along with a third church in the town of Batticaloa, on the east coast.
Around two hours later two more blasts were reported on the outskirts of Colombo. It was later reported that the second of those reported blasts was from police opening fire, not an eighth bomb.
The victims included Shantha Mayadunne, a popular television chef who was breakfasting with her daughter at the Shangri-La hotel when it was attacke
The Foreign Office said it was “urgently seeking” information from authorities in Sri Lanka.
A spokesman said: “We are aware of reports of a number of explosions in Sri Lanka, including Colombo, and we are urgently seeking information from the local authorities.
“British nationals in Sri Lanka should follow the instructions of the local authorities and check FCO travel advice for updates.”
Photos circulating on social media showed the roof of one church had been almost blown off in the blast, with the floor littered with a mixture of roof tiles, splintered wood and blood.