Up to 150 men of Indian background, some armed with baseball bats and hockey sticks, on Monday night rallied in Wigram Street, protesting what they say is a pattern of violence against students and migrants.

The demonstration followed reports a young Indian man had been assaulted by a group of men of Middle Eastern appearance.

The assault led to a retaliatory attack on three Middle Eastern men in nearby Marion Street and came less than a month after a petrol bomb was hurled through the bedroom window of a 25-year-old Indian hospitality graduate in nearby Harris Street.

Parramatta local area commander, Superintendent Robert Redfern, said he believed the attacks were ``opportunistic'' and not racially motivated.

``They are young people, often students, often working working the jobs young students work ... and they are therefore at risk opportunistically of being assaulted in the early hours of the morning or very late at night,'' he said.

Superintendent Redfern said police worked closely with the Indian community and had reduced the area's crime rate.