Colombo: Sri Lanka on Monday declared a countrywide curfew to control the spread of communal violence following some of the worst mob attacks directed at the country's minority Muslim population since the Islamic State group claimed the deadly Easter Sunday bombings.

A Sri Lankan government soldier secures the premises of a Catholic church as devotees leave after Sunday Mass at a church in Colombo. Credit:AP

In the weeks since the bombings, which killed more than 250 people, tensions have remained high across the island nation. The government has intermittently blocked social media to avoid the spread of misinformation, and police have declared curfews in some cities after smaller clashes.

But in a sign of growing concern that overnight attacks on Muslim homes and mosques could grow out of control, the government declared a nationwide curfew, from 9pm to 4am.

The Muslim Council of Sri Lanka said attacks had been reported in at least five towns in the North Western province, which has traditionally been home to both Sinhalese, who are largely Buddhist, and Muslims.