AN ATTACK on a 12-year-old boy by a suspected mental health unit patient has led campaigners to fear their predictions are coming true.

Tracy Ashley says her son Christopher, 12, is now too frightened to walk to school after being throttled by a patient from Bethlem Royal Hospital, Beckenham.

She is now drawing up a petition to demand better security and stop the unit expanding from 29 to 89 beds - something long opposed by campaigners who feared for community safety.

The attack happened on October 4 in Monks Orchard Road, Beckenham, just outside the hospital and is the latest in a string of incidents involving patients.

Christopher was walking the family dog with his friend at 6pm when the pair saw a man staring at them from across the road.

They ran off but the attacker gave chase, catching Christopher, throttling him and threatening to kill him.

He eventually let go and the terrified boys ran home.

Police were called and Christopher gave a description. The family say a manager identified him as a patient.

The following night mother and son walked the dog together.

They were horrified to see someone they thought was the same man, with a carer, in the hospital grounds.

Mrs Ashley, 34, said: "My son's confidence has just died while I'm losing sleep and feeling physically sick.

"It's not fair we are too frightened to walk down our own streets."

Kelsey and Eden Park councillor Rod Reed said: "Once again, it raises the whole spectre of poor security and does not inspire much confidence in the expansion of the medium-secure unit.

"We can't have a situation in Beckenham where innocent members of the public are attacked."

Mrs Ashley claims male patients have flashed at schoolgirls and neighbours of the hospital have found patients sitting in their living rooms watching television.

The mother-of-three says residents and shopkeepers are frequently intimidated by people standing and staring.

She added: "It makes me sick. Do we have to wait until someone is seriously injured before security is addressed?"

However, the hospital says there is nothing at this stage to confirm it is anything to do with a security breach.

A spokesman for South London and Maudsley NHS Trust, which runs the hospital, says officials have spoken to the family, are concerned about their distress and will write to them after carrying out an investigation.

The spokesman added patients are allowed to leave because the hospital is not a prison and so the attack is a matter for police.