Police opened fire when rival groups of Moslems rioted during Islamic celebrations in the western town of Mangrol and at least 13 people were killed, news reports said Monday.

At least 50 people were injured in the clash Sunday night in Mangrol, about 590 miles southwest of New Delhi, The Times of India said.It was not immediately clear how many people died from police fire and or when the Moslems battled each other with swords, steel bars, stones and bottles, according to news reports.