Extra police are patrolling the centre of Peterborough in the wake of four nights of violence.
Ghulam Shabbir says the trouble has been sparked by newcomers
Community leaders joined police in appealing for calm after running street battles between the Pakistani community and asylum seekers.
A series of clashes between Pakistani, Afghan and Iraqi men in a small part of the city have left homes damaged and burned out cars on the streets.
Extra police, some from as far afield as Essex, have been drafted in.
Pakistani Community Association chairman Ghulam Shabbir said: "I would appeal to all of the people to give us the time to work with the police and other members of the community so we can come to an amicable resolution of the whole problem."
Mr Shabbir said much of the fault lay with the anti-social behaviour of the newcomers to the city over the past 18 months.
He said in the first incident, about 15 to 20 youths from the Pakistani and Kurdish communities, surrounded by gangs of up to 100 spectators, were involved in a fight using sticks and hammers.
He said one man was badly injured, two houses and two cars had been set alight and windows broken at two houses.
On Wednesday night gangs of youths returned, smashing car windows and setting light to a third car.
On Thursday, Mr Shabbir told BBC News Online tension had been brewing because of the "perceived" anti-social behaviour by Kurds and some Afghan youths.
But he said the catalyst for the trouble was "inappropriate behaviour" towards a Pakistani woman.
Cambridgeshire Police Ch Supt Nigel Sunman said the long-established Pakistani community and the asylum seekers had clearly articulated what was disturbing the other community.
"It is cultural differences in the large part. We are getting to understand those issues and what we are trying to do is feed back to each of the communities what it is that is antagonising them," he said.
Peterborough City Council's director of community services, Sheila Grant, said the authority was doing all it could to end racial tension between the city's four communities.