Authorities says clashes between Buddhists and Muslims have killed three Muslims and wounded at least 75 people in southern Sri Lanka.
The violence late Sunday in the coastal towns of Aluthgama and Beruwala followed a rally by the hardline Buddhist group, Bodu Bala Sena, and was reportedly triggered by a local dispute.
Residents say BBS supporters set several homes on fire and attacked mosques. Authorities have imposed a curfew in the popular tourist region.
Sri Lankan Justice Minister Rauf Hakeem accused his own government of not taking measures to prevent the unrest. He said authorities allowed the BBS to hold their gathering without providing extra security for Muslim residents.
The BBS, which has been engaged in an anti-Muslim campaign, is said to have support from the government. Many of those involved in violence against Muslims and Christians reportedly go unpunished.
Sri Lankan President Mahinda Rajapaksa vowed an investigation into the violence and urged all parties to exercise restraint.
United Nations says U.N. High Commissioner for Human Rights Navi Pillay expressed alarm at the communal violence and urged the government "to do everything it can to arrest this violence, curb the incitement and hate speech which is driving it and protect all religious minorities."
The U.S. Embassy in Colombo also condemned the violence and urged authorities to bring those responsible to justice.
Sri Lanka's government has come under fire for not doing enough to protect Hindus, Muslims and Christians since the end of a nearly three decade-long civil war.
The military defeated the Tamil Tiger rebels in May of 2009, with both sides accused of human rights violations in the conflict.