Large-scale disorder broke out in Leicester on Saturday, with police and community leaders calling for calm.
Officers tried to hold back crowds amid tensions involving mainly young men from sections of the Muslim and Hindu communities.
Police said two arrests had been made, and that the trouble flared up after "an unplanned protest".
It is the latest of several incidents, including violence after an India and Pakistan cricket match on 28 August.
A significant police operation will remain in the area in the coming days.
Suleman Nagdi, of the Leicester-based Federation of Muslim Organisations told the BBC: "What we have seen on the streets is very alarming.
"There have been problems in the community since the India and Pakistan cricket match and while that game often sparks gatherings they have not in the past turned this ugly.
"We need calm - the disorder has to stop and it has to stop now. There are some very dissatisfied young men who have been causing havoc.
"We need to get the message out that this must end and try to do this through parents and grandparents talking to their sons."