The device, dubbed the "CCTV Lump", has a two-tonne base which can accommodate up to four cameras. It is carried on a lorry and assembled in 45 minutes.

Images are recorded on a CD and can then be downloaded and viewed.

Chief Inspector Bill Gaskins, who designed the equipment, said it had already had a significant impact in reducing anti-social behaviour.

He added that Gloucestershire Police could move the camera to trouble spots at short notice.

Meanwhile, police officers will patrol Gloucester's car parks on Thursday as part of a high-visibility operation to prevent car crime.

Drivers will also be offered advice on protecting their valuables.