Sri Lanka blocked access to Facebook and WhatsApp after Christian attacks on mosques and Muslim-owned stores Sunday in reaction to a Facebook post.
Nalaka Kaluwewa, director general of Sri Lanka's information department, said the social media was blocked as "a temporary measure to maintain peace in the country."
Reuters reports that the Muslim author of a Facebook post that read "1 day u will cry" was arrested Sunday after Christians interpreted the post as threatening violence.
The South Asian nation has been on edge since the Easter morning bombings of churches and hotels that killed more than 250 people.
The Roman Catholic faithful in Sri Lanka's capital attended Mass Sunday for the first time since the Easter bombings of churches and hotels that killed more than 250 people.
Soldiers and police armed with assault rifles patrolled the neighborhood around the churches.
Two days after the Easter attacks, the Islamic State claimed responsibility.
Prime Minister Ranil Wickremesinghe said last week that all of the jihadists responsible for the Easter attacks have been arrested or killed but that the country is still threatened by "global terrorism."
Sri Lankan authorities have said two little-known domestic Islamist groups were responsible for the Easter bombings, the National Thowheeth Jamaath (NTJ) and Jamathei Millathu Ibrahim (JMI).