Violence between Asians and Afro-Caribbeans in Oxford last week is believed to have been sparked by the arrival of a group from London, community leaders said today.

They insisted that there was no rift between members of the two communities in Oxford and that relations were friendlier than in any other city.

Police said they sent 20 officers to the John Radcliffe Hospital after violence between rival groups erupted at Cowley and threatened to spread when one victim was taken to the accident and emergency unit.

Mumtaz Fareed, chairman of the Asian Cultural Association in Manzil Way, east Oxford, said he had had 60 phone calls from Asian and Afro-Caribbean people who were outraged by what they had read about the incident.

He said: "They were upset. In Oxford the two communities are friendlier than in any other city. We want good relationships with the police and the media. We don't want any rifts."

Mr Fareed denied that gangs of Asians and Afro-Caribbeans had gone to the hospital. He said the only people there were the family of an Asian man who had been attacked and a group of Afro-Caribbean people visiting another injured man.

He said: "I understand that the African Caribbeans were from London. They were on a different side of the accident and emergency department to us. The people who were there were visiting the victims who were injured. They did not become gangsters."

Oxford city councillor Robert Evans, a member of the Afro-Caribbean community, said: "I am not aware of any rift between the Asian community and the African Caribbean community in Oxford. I heard that the African Caribbean gang was from London. Just because there were a couple of people fighting and some are Asian and some are African Caribbean, does not mean it is a racial issue.

"The two communities are very together in some ways. There is quite a strong relationship. Asians have given us support for our plan for an African Caribbean Centre."

Police believe the violence which broke out on a recreation ground between Herschel Crescent, Littlemore, and Barns Road, Cowley, may have followed a robbery at the Q8 filling station in Oxford Road, Cowley, on Wednesday.

Police said they had identified both factions involved in that incident and later violence at the recreation ground.

Five youths were now on bail pending further inquiries into both incidents.

Police confirmed that community leaders had been asked to help with the inquiry and officers were investigating a possible link with a group from London.

Oxford's city and race relations officer, WPc Derrice Alleyne, will make contact with community representatives when she returns from leave. Oxford Area Commander, Supt David McWhirter, said: "We are investigating both of these incidents and committing extra resources to deal with any possible recurrence."