A homeless man slashed a security guard with a broken peanut butter jar at Oxford's John Radcliffe Hospital, a court was told.

Two security guards were escorting Nigel Fletcher, 33, from the hospital on October 25 last year when he smashed a jar of peanut butter against the wall and used a shard of glass to cut Rachael Collins, one of the guards.

Jenny Jonckheer, prosecuting, said Fletcher was asked by staff to leave after he had spent the night sleeping at the hospital.

She told Oxford Magistrates Court yesterday: "On being asked to leave, he became aggressive and abusive against the staff.

"They in turn called the security guards and asked them to escort the defendant from the premises. He removed a jar of peanut butter from his jacket and smashed it against a wall, and took a piece of glass and lunged towards Miss Collins.

"The glass cut Miss Collins on the forearm, causing a two centimetre cut.

"The defendant was then restrained. The glass was taken from him and the police were called."

Fletcher admitted assault occasioning actual bodily harm.

Tony Davis, defending, said his client had a serious personality disorder.

He said Fletcher had not intended to harm Miss Collins, but had instead been trying to cut himself.

Magistrates gave Fletcher, who has been on remand since October 26, an 80-day prison sentence.