DOZENS of people were evacuated from several industrial units on the outskirts of Durham City for more than four hours on Monday following a fire involving acetylene cylinders.

Firefighters were called to Durham Pumps, on the Belmont Business Park, at 9.15am.

Durham City station manager Graeme Metcalfe said: “Workers at Durham Pumps were using a oxygen tank as part of an oxy-acetylene set.

"Acetylene cylinders are extremely dangerous when involved in a fire.

“We believe a fire has been caused by a flashback – a fault where there has been some sort of leak.

“There has been an ignition in the supply tubes it has gone back into the valve assembly and damaged the cylinder.

"Consequently we have had to follow a procedure.”

He added: "That involves cooling and monitoring the cylinder and establishing an exclusion area.

“About 50 people have been evacuated from several premises. Crews assisted people with getting out and moving their cars. They have done a good job.

“We have been conscious of limiting the effect to the local community and environment - working with the police to manage the traffic flow.”

Two two appliances and special rescue unit are attending the incident. The exclusion zone was lifted at 1.45pm.