COLOMBO, Sri Lanka — Sri Lanka’s government has temporarily blocked social media and messaging apps following a flare-up of communal violence, the third time it has taken such a step since last month’s Easter attacks that killed more than 250 people, an official said Monday.

The government acted after an exchange of accusations between two people on Facebook led a mob to attack a Muslim-owned shop Sunday in the Catholic-majority town of Chilaw, said Nalaka Kaluwewa, the chief of the Information Department. Police imposed a curfew in the town, located about 50 miles north of Colombo, the capital, following the violence but lifted it Monday morning.

Kaluwewa said the government temporarily blocked social media in order “to prevent misinformation from being circulated and also to prevent spreading of information that would harm communal harmony.”

Previous blocks on social media and messaging apps imposed following the April 21 suicide attacks on churches and hotels were lifted after several days.

Police spokesman Ruwan Gunasekara said police have arrested a 38-year-old Muslim businessman, Abdul Hameed Mohamed Hasmar, for allegedly writing the Facebook comments that sparked the violence.

Local media reported that residents in the area angered by the comments stoned Hasmar’s shop.

Tensions have been running high in the Buddhist-majority Indian Ocean island nation since the attacks by seven suicide bombers who struck two Catholic and one Protestant church and three luxury hotels. The Islamic State group claimed responsibility for the attacks, carried out by a local radicalized Muslim group.

Since then, the government has intensified security across the country, with armed policemen and troops being deployed to protect schools, churches and key government offices.

On Sunday, the Catholic Church held the first regular Sunday Mass since the attacks amid tight security. Sunday services had been canceled the two previous weekends for fear of more attacks, leaving the faithful to hear Mass via live TV transmission from the residence of Cardinal Malcolm Ranjith, the archbishop of Colombo.