Near simultaneous explosions in at least three Sri Lankan churches and three luxury hotels have killed at least 290 people and wounded over 500.

Three of the explosions took place at Catholic churches, while three others were reported at the Cinnamon Grand, Kingsbury and Shangri-La hotels, located in the heart of the capital Colombo.

Officials said at least 45 people had been killed in Colombo.

Another 67 were killed in an attack on a church in Negombo north of the capital, with another 25 dead at a church in the town of Batticaloa, in the east of the country.

The nature of the blasts was not immediately clear and there were no immediate claims of responsibility.

Sri Lankan President Maithripala Sirisena expressed shock at the explosions and appealed for calm.

Prime Minister Ranil Wickremesinghe wrote on Twitter: “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. Please avoid propagating unverified reports and speculation. The government is taking immediate steps to contain this situation.”