Teenage arsonists have driven a vulnerable man out of his Oxford home.

They started two fires at the Rose Hill flat of Graham Foster - and on one occasion tried to create an explosion using household chemicals and a microwave.

On Friday, they struck the Rivermead Road flat again, starting a blaze that destroyed a window, mattress and sofa.

Mr Foster, who is in his late 20s and has mental health problems, has now abandoned his home and a neighbour who lives in the flat above has asked for new accommodation from Oxford City Council because of her fear over the attacks.

Police today appealed for witnesses to come forward to help them catch the arsonists before they pick on someone else.

DC Lewis Mayling, of Oxford CID, said: "There is nothing in police records to show any other motives to pick on him as an individual - it's just the case that they are bullies of vulnerable people."

Police are investigating two fires, an attempted arson and two break-ins at the flat. They believe the same group of teenagers are responsible.

On July 28, the gang kicked in a panel of Mr Foster's door to get in, before loading chemicals into his microwave.

DC Mayling said: "They put knives, forks, plastic, hairspray and baked bean cans in the microwave.

"They must have left it thinking it would explode and set fire to the flat, but it did not really light - it just fused the microwave and left a bad smell."

The next day papers on a chest of drawers in the flat were set alight, causing a small fire.

DC Mayling added: "On certain occasions there has been one or two of them, on other occasions there has been a number of them. We suspect a group of youths that have been responsible for other antisocial behaviour around the estate."

A 14-year-old boy was arrested in relation to the microwave incident, but was released without charge. No other arrests have been made.

Anyone with information on the incidents is urged to call police on 08458 505505 or Crimestoppers on 0800 555111.