An unlikely bunch of onlookers helped an off-duty policeman to snare a robber as he tried to hold up a bank with a fake assault rifle while on day release.

Al-Fodday Fofanah was foiled in a plan to rob Barclays on Borough High Street in south east London while using a stocking to disguise his face.

The 30-year-old aimed the deactivated weapon at cashiers and demanded money as terrified customers fled out into the street during the hold up on July 18 last year.

Realising the robbery was doomed to fail Fofanah ran outside, where he was confronted by an off-duty police officer who tried to call for back-up.

But the suspect fled along the high street - prompting the police officer to chase him with help of the assistant bank manager and a trainee ambulance driver.

A roofer and his colleague who saw the furore then pulled his van onto the pavement in front of Fofanah and tried to apprehend him, knocking him down with the vehicle and forcing him to flee down an alleyway.

The pair then chased the suspect through a series of alleyways until he was knocked down by another pedestrian, prompting him to wave his assault rifle at waist height in a bid to frighten them.

But the criminal again fled as an ice cream vendor who was parked nearby jumped out of his van to give chase towards Guy's and St Thomas' Hospital, where a security guard wrestled the gun from Fofanah's hands and pinned him down with the help of the ice-cream man.

The men held him down on the ground until police arrived and arrested him.

Fofanah, who had been on day release from Ford Open Prison, admitted two counts of attempted robbery, two counts of possession of an imitation firearm and escape from custody at Woolwich Crown Court on Wednesday.

Detective Chief Inspector Paul Johnson said: "A number of people assisted with detaining Fofanah following the attempted armed robbery and without their help there is every possibility that he may have got away.

"I would like to thank the members of the public who demonstrated an enormous amount of bravery in confronting Fofanah especially those who showed little fear in tackling him to the ground and keeping hold of him until police arrived."

The Good Samaritans who helped secure his arrest are today receiving a Commissioner's Commendation award in a ceremony at Scotland Yard.

Fofanah will be sentenced at Woolwich Crown Court on February 21.