A festival organised to promote the diverse cultures of the city of Peterborough was marred by violence as Pakistani and Iraqi groups clashed.
The groups clashed in May when property was destroyed
The weekend-long festival was set up by the city's Indian community to showcase its culture, music and food.
But police said clashes erupted between groups at the East of England Anand Mela on Saturday and further violence followed in the city on Sunday.
On each occasion gangs of youths were involved in the fighting.
On Saturday police were called to the festival site in the Embankment area at about 2130 BST to find chairs being thrown and fights between about 90 youths.
Pub windows smashed
As officers arrived the groups scattered from the festival towards the city centre where fighting continued.
Extra officers were called in and the fighting eventually petered out.
However, problems flared again on Sunday night in Gladstone Street - an area which saw several nights of fighting between the two communities in May - when about 100 youths fought in the streets.
The trouble started after a group of Iraqis were allegedly thrown out of the Gladstone Arms pub. Some of the pubs windows were smashed before a group of Pakistani youths confronted the Iraqis.
Police officers were quickly at the scene to calm down the situation and there were no arrests.
A police spokesman said one man was injured in the fighting and taken to Peterborough District Hospital.
"Quick and positive police involvement has helped to quickly defuse a situation which could have been much worse," he said.
Organisers of the festival said it attracted a record number of people this year and was a success.