A fire that tore through a shopping centre construction site in Bath has brought the project to a standstill while fire investigations are carried out.

The blaze, on Multi Development’s£360 million Southgate project, is reported to have started when asphalt leaked out of a faulty heater, although the developer said that the exact cause was not yet known.

Eyewitnesses reported hearing a loud explosion followed by flames shooting 50 ft in the air. The fire brigade was on site within five minutes of the explosion and local shops were evacuated.

A Multi Development spokesman said: “Initial indications suggest the damage is relatively minor, however a full survey will be carried out over the next few days to ascertain the complete extent of the damage. A full independent investigation will take place to determine the precise cause of the fire.

“The site is closed today while the fire service carry out final safety checks and the contractors, Sir Robert McAlpine, hope to resume normal production within the next 48 hours.”