An off-licence worker chased after a robber who threw a knife at him, narrowly missing his head.

James Adams, 20, gave chase after the man tried to raid Threshers in Iffley Road, Oxford.

The offender threatened him with a knife and demanded he hand over the contents of the till.

When he refused, he threw the knife at him. It flew over his left shoulder and bounced off a wall. The cashier then pursued the man out the shop towards the city centre for 300 yards before he lost sight of him.

Mr Adams, a student at St Catherine's College, said he felt lucky not to have been seriously injured.

He said: "I was more angry than anything else. As far as I'm concerned people don't come in and wave knives at me.

"I was worried he might hurt me with it. Obviously, it was a dangerous situation, but I wasn't worried for my life at the time." The offender told Mr Adams, of east Oxford, to put cash from the till in a Co-op plastic bag, but he refused and shouted at the man.

Det Con Matt Rogers, of Oxford CID, said: "This was an incident in which the shop attendant was extremely lucky not to have received potentially serious injuries.

"We are obviously keen to identify and arrest this offender and put him before the courts.

"The public need to be aware he is a violent man and not to approach him.

"They should contact us if they know his identity."

Police immediately searched the area but the offender was not found. The knife was recovered and has been sent for forensic examination. The offender was black, about 6ft 2in, in his 30s, had close cropped hair and wore a dark blue top. The incident, which lasted about a minute, took place at 5.50pm on Sunday. Nothing was taken.

Police advise shop workers not to try to tackle armed robbers.

Anyone with information should call Oxford police on 01865 266333, or Crimestoppers anonymously on 0800 555111.