A 200m cordon was set up around an outdoor storage building on a north Suffolk industrial estate following a fire which threatened acetylene tanks.

The exclusion zone was set up by firefighters at the site of Oranmore Pre-Cast in Mundford Road, Brandon shortly before 5pm this afternoon because of the danger the two tanks could explode threatening the safety of staff, although they had already evacuated from offices around the building before fire crews had arrived.

Station manager Tim Edwards, who is based at Kings Lynn, said fire crews had largely extinguished the fire, except for one or two smaller blazes within the building, by 7pm, although crews would be maintaining a watching brief throughout the night to monitor the tanks.

He added that thermal imaging cameras were constantly monitoring the temperature of the tanks and he was satisfied there was no imminent danger of explosion.

However, he said there had been an explosion while the crews were fighting the fire which may have been caused by an acetylene tank, adding the 200m cordon was a standard procedure for incidents involving acetylene because it is a flammable gas.

Oranmore specialises in the manufacture of hollowcore floors and precast stairs, and the 5,000 sq ft concrete building, which was damaged internally, stored wood.