A mosque official said the attacks were triggered when several people, including some Buddhist monks, demanded a search of the main building after soldiers had inspected a 105-acre (43-hectare) pond nearby.
However, police have obtained Facebook, WhatsApp and Telegram chats with two of the suspects arrested in connection with a plot to attack a synagogue in Ahmedabad, Ubed Ahmad Mirza, a lawyer, and Stimberwala Mohamed Kasim, a hospital technician.
On April 21, a wave of jihadi suicide bombings targeted churches and hotels, killing more than 250 and injuring about 500 others.
In a separate TV address, Police Chief Chandana Wickramaratne warned police will take stern action against rioters, and constables have been issued orders to use maximum force.
Dozens of people have been detained since the Easter Sunday attacks, and amid the heightened security, police have banned parking near schools and students are allowed in after checking for explosives.
Prime Minister Ranil Wickremesinghe said in a speech to the nation that security forces had brought the violence under control but the government chose to impose the curfew to stop the violence from spreading to other parts of the country. In the town of Hettipola at least three shops were torched. "It was very much like the previous instances of anti-Muslim attacks", he told The Hindu on Tuesday.
In the NWP, attackers systematically targeted mosques for two days, local clerics told AFP.
A police source said police had fired tear gas to disperse mobs in some places in North Western Province.
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But he failed to bend attitudes among leaders who fear the U.S. and Iran are inching towards war. The exact timing and details of Monday's meeting with Pompeo are still unclear, diplomats said.
Crucially, one individual brazenly admits he was part of the mob in what appears to be a Facebook live stream and encourages others on the island to follow his path, once again bringing into the spotlight the use of social media in spreading hate.
Platforms were similarly blocked after the Easter attacks.
Prime Minister Ranil Wickremesinghe sending a message through his official Twitter account asked the public to be calm and not be influenced by false information.
The Muslim shopkeeper's comment was taken by local Christians as a warning of an impending attack.
Elsewhere in the province north of Colombo rampaging mobs, who outnumbered police and security forces, set fire to Muslim-owned shops, vandalised homes and smashed windows, furniture and fittings inside several mosques.
On Sunday, the Catholic Church held the first regular Sunday Mass since the attacks amid tight security.
Public schools completed their reopening from extended Easter holidays after the attacks, but attendance was low, according to education authorities.
Muslims constitute some 10% of Sri Lanka's 22 million people; Christians make up around 7.5% of the population.