A damp and chilly start to spring failed to stifle the exuberance of thousands of 'May Morners' who turned out to see in the new season in traditional fashion.

Crowds gather on Magdalen Bridge

Many of the estimated 12,000 crowd at Magdalen Bridge in Oxford this morning had obviously heeded the gloomy forecast, many dressed head to toe in rainproof clothing.

Others came straight from college balls wearing black tie and evening dress.

On the strike of 6am, a hush descended as the Magdalen College Choir began their traditional recital to the 8,500 allowed on the bridge between barriers placed at The Plain and High Street.

Police estimated there were at least another 3,500 pressed against the barriers on either side.

The cool temperature and a brisk easterly breeze did not prevent about 20 people from scaling tall metal barriers along the parapets of Magdalen Bridge and leaping into the River Cherwell, despite signs and police warnings of the risk of injury. No-one was hurt.

Thames Valley Police handed over responsibility for the event to Oxford City Council, whose private security officers were on hand to limit numbers.

Once again the police adopted a low-key approach to the event, deciding that an amnesty would be in operation in one of the city centre's alcohol-free zones, but people were asked to leave bottles and cans in bins before they were allowed on to the bridge.

Chief Insp Stuart Craik, of Oxford police, said: "One young woman was assaulted and suffered a gash to her forehead. But otherwise it seems to have gone off very peacably."

The woman was taken to the John Radcliffe Hospital. Two teenage girls were arrested in connection with the incident.