COLOMBO (AFP) - Sri Lanka's Muslim minority held shortened Friday prayer services as religious tensions gripped the island after clashes with hardline Buddhists killed four people, an official said.

The Muslim Council of Sri Lanka (MCSL) said Islamic clerics instructed mosques to conduct shorter services and asked the faithful to disperse peacefully after lunchtime prayers.

"The Ulamas (scholars) asked mosques to ensure shorter sermons and in some places they started prayers earlier than on other Fridays," MCSL President N M Ameen told AFP.

He said there were no incidents reported although the police had anticipated trouble after Friday prayers and stepped up security in the capital and elsewhere.

Muslim-owned businesses shut down in Sri Lanka's capital on Thursday to protest against deadly riots by extremist Buddhists, defying President Mahinda Rajapakse's plea to stay open.

Shops and restaurants in central Colombo were shuttered following the riots in two mainly Muslim coastal resorts that killed four people and saw hundreds of homes and businesses set on fire.

The Muslims were protesting against the Buddhist Force, or BBS, and the police failure to protect their minority community which accounts for about 10 percent of the 20 million population.