Two Muslim teenagers were beaten outside a New York City mosque by an attacker who shouted slurs at them, a rights group said on Monday, calling for police to investigate the incident as a bias crime.

The attack early on Sunday was at least the third involving Muslims in the United States over the weekend. A law enforcement source said investigators had ruled out the incident as a bias crime.

The New York chapter of the Council on American-Islamic Relations, or CAIR, said in a statement that a 16-year-old boy was attacked outside Brooklyn's Muslim Community Center as he took a break from prayers,