Businesses were warned to batten down the hatches last night as police increased patrols on the city’s streets as a precaution against copycat rioting.

It came after an arson attack on McDonald’s in Risinghurst when a petrol bomb was flung through a window as staff locked up for the evening on Monday.

Police yesterday linked the arson with several other crimes in and around Barton on Monday night and issued a 12-point guide to shop keepers.

They warned stores to remove loose items which could be used as missiles and take expensive items out of shop windows.

Graham Jones, of business group ROX, said: “I know the owner of the McDonald’s very well. This affects people’s jobs and it is rather distressing.

“I think everyone in the business community is just watching and waiting.”

Police confirmed they were linking four incidents in the Barton area with the McDonald’s arson.

They were searching for offenders who stole petrol from the Shell garage, in London Road, at around 11.30pm.

Officers were also looking for arsonists who set light to a car in Barton Road at 12.50am.

A number of people were also seen rummaging through a skip for weapons close to McDonald’s.

Emma Baker 32, of Colemans Hill, witnessed the aftermath of the McDonald’s attack, which happened while staff were inside locking up.

She said: “I went to the cash point just after midnight and there was smoke pouring everywhere.

“A bottle with a rag hanging from it had been thrown through the window.

“All of a sudden the police started turning up and another fire engine. The smoke was rancid.”

A 26-year-old man has been arrested on suspicion of arson and was last night being questioned by police.

Last night three Thames Valley Police riot squads were on the streets of London as the force also increases patrols on Oxford’s streets.

Superintendent Amanda Pearson was confident the force still had enough officers to deal with the situation, and added there were no plans to cancel the Oxford United match against Cardiff City.

“What we are not seeing is a widespread number of incidents spread across the city.

“I am ensuring personally that I’ve got enough police officers and PCSOs to deliver policing.

“The Oxford United match is going ahead. As far as I am aware there is no specific information of any threat.”

She added the force would consult with the club in the run-up to kick-off and said supporters should check the official club website for any updates.

ljones@oxfordmail.co.uk