Staff and customers were forced to evacuate two Truro stores on Monday after fears that a wall was about to collapse onto a gas main and cause an explosion.

One of the main roads into Truro was also closed, causing traffic chaos in the city centre.

The drama began at 11am when a worried shopkeeper contacted police to say that a wall behind the Staples store next to Morlaix Avenue had been damaged a few days previously and was now looking as though it may collapse. Underneath the wall was a three-inch gas main.

An emergency gas crew were called to the scene immediately, to cut off the supply, while staff and customers at the Staples and Currys stores were asked to leave the area for their own safety, at 11.20am.

Alison, who was working at Staples at the time, said: "The first we knew about it was when the manager and assistant manager came out and told us that we had to get out of the building. The wall that's on the side of the road was apparently hit by a vehicle just before the weekend and because the traffic is going by, making vibrations, the wall is going further and further in and there was a danger of it collapsing."

Many of the staff went to the nearby Tesco store for a coffee break, before being allowed back into the stores at around 1pm, when there was no further danger of an explosion.

At the same time, police closed the A390 at the bottom of the hill in Morlaix Avenue, by the roundabout with Tesco.

Officers urged locals to avoid the area, as large tailbacks formed and other parts of the city became congested as drivers attempted to find alternative routes.

Diversions were put in place, to keep traffic out the area while large areas of the wall were removed.