Riot police made two arrests after 200 youngsters of South Asian origin threw firecrackers at police officers on Sunday in an incident said to be linked to plans for a right-wing march through the town of Luton.
Communal tensions have risen in Luton - a town with a substantial population of Pakistani-origin people - ever since a small group of Muslims held an anti-war protest during a march by British soldiers returning from Iraq five months ago.
The local Bedfordshire Police said 50 officers had been called in Sunday afternoon after a small team of constables and police volunteers had been attacked by about "200 members of the younger Asian community".
Police said the incident was linked to plans by far-right groups to take out a march through the town Sunday, but also said the Asian protest was held "for no apparent reason" because the march had already been banned.
Marching plans were scotched after the British home minister last week imposed a three-month ban on public processions in Luton by four groups - March for England, UK Casuals United, United People of Luton and English Defence League.
Bedfordshire police said in a statement: "(Sunday's) disorder follows weeks of engagement and public consultation by Bedfordshire Police and Luton Borough Council in response to tensions within the community after the town was identified as a potential location for a march by right-wing supporters."
Chief Superintendent Andy Frost said: "There has been extensive public consultation and work behind the scenes to ensure Luton was not the chosen venue for any kind of march or protest but it would seem that for no apparent reason disorder has broken out in Bury Park."
Police previously said residents and businesses feared a repeat of the violence and disorder, including damage to property and assaults on individuals, which erupted during previous processions by far-right groups in Britain.