Security forces stood guard outside Kollupitiya Jumma Masjid (Mosque) in Colombo during Friday prayers, as there were growing fears over retaliatory sectarian violence against Muslims after the deadly Easter attacks in the Sri Lankan capital.
Police set up fences and security checks as some patrolled the area with police dogs.
As many as 10,000 soldiers have been reportedly deployed to conduct security searches and guard religious centres.
Many members of the Muslim community have reportedly abandoned their houses and fled over bomb scares, lockdowns and security sweeps.
At least 253 people were killed and hundreds injured on 21 April, Easter Sunday, during the Easter weekend, in eight seemingly coordinated explosions which rocked hotels and churches across the Indian Ocean island.
The initial death toll of 321 was revised down to 253 by the Sri Lankan Health Ministry, citing an error in calculation.