The hotels and one of the churches are in the South Asian island nation's capital, Colombo. The other two churches are in Negombo, a Catholic majority town north of Colombo, and the eastern town of Batticaloa.
A local security official told AP that the explosions have caused multiple fatalities among worshipers and hotel guests.
The official said they suspect the blasts at two churches were carried out by suicide bombers.
A source in the police bomb squad said that one of the explosions was at St Anthony's Church in Kochcikade, Colombo. "Our people are engaged in evacuating the casualties," a police source said.
Colombo National hospital said several wounded had been brought in for treatment, Al Jazeera reported.
St Sebastian's church at Katuwapitiya in Negombo posted pictures of destruction inside the church on its Facebook page, showing blood on pews and the floor, and requested help from the public.
There were no immediate claims of responsibility.