POLICE were on high alert in Maidstone today after the armed hijack of a prison van this morning in Central London.

Three prisoners escaped when two men, one disguised as a postman, stopped a Securicor van, shooting the driver in the knee and hitting a security guard with a gun.

The attack took place at about 9.10am outside Inner London Crown Court, near Elephant and Castle in Southwark.

Another prison van on the road was immediately diverted to Maidstone Law Courts, as a precaution in case of further attack. Armed police and dogs surrounded the building for most of the day.

On board was a category A prisoner due to appear in the capital with the other escapees to face charges related to a £1.25 million security van robbery in March.

The man, who spent the afternoon in Maidstone Law Court cells before being returned to prison, is understood to be serving a life sentence for murder.

A Kent Police spokeswoman said: "Kent Police has been involved in a security incident at Maidstone Crown Court. "We are not, at this stage, able to release details of the nature of the incident or our involvement in it."