Sri Lankan police have fired tear-gas and enforced a curfew in two coastal towns popular with tourists in an attempt to end clashes between Muslims and Buddhists that threatens to set off wider religious violence.

The police said on Sunday they were widening a curfew in Aluthgama to the neighbouring town Beruwala, a predominantly Muslim area, after violence threatened to take hold in the region.

According to the AFP news agency, the two groups attacked each other with stones in fighting over the weekend - the latest in a series of religious clashes to hit the island nation.

A police spokesman said trouble began when a group led by Buddhist monks tried to march in an area with a sizeable population of Muslims, who are a minority in the mainly Buddhist country.

"The curfew was declared to bring the situation under control," the spokesman said.

"The curfew was extended to a neighbouring area to prevent an escalation of clashes."

"Several Muslim-owned shops have been burned and homes attacked," a resident in Beruwala told AFP.

"Some Buddhists are deliberately targeting Muslims. But unfortunately police have not been able to protect the minorities," Hilmy Ahmed, spokesperson of Muslim Council of Sri Lanka, told Al Jazeera.

"A petty feud between two individuals has been allowed to take a religious tone. The extremist Buddhists led by Bodu Bala Sena attacked Muslims and are still in the area despite curfew."

There were no reports of arrests but dozens of people were said to have been injured.

Appeal for restraint

President Mahinda Rajapaksa, who is in Bolivia attending the G77 summit, has called for restraint with the promise that the government will not allow anyone "to take the law into their own hands".

"An investigation will be held for law to take its course of action to bring to book those responsible for incidents in Aluthgama," he said in a Twitter message.

The latest unrest came weeks after Muslim legislators asked Rajapaksa to protect their minority community from "Buddhist extremist elements" blamed for a recent spate of hate attacks.

Muslims make up about 10 percent of Sri Lanka's 20-million population.

Nationalist Buddhist groups, including the Bodu Bala Sena, accuse religious minorities of having undue political and economic influence on the island.

Videos posted on YouTube have shown mobs led by Buddhist monks throwing stones and smashing a Christian church in southern Sri Lanka in January, and attacking mosques while police looked on.

Senior Buddhist monks have also been caught on video threatening violence against their moderate colleagues who advocate tolerance.

Rajapaksa, who is a Buddhist, warned monks in January last year not to incite religious violence.