FIREFIGHTERS have urged allotment holders not to keep gas canisters in their sheds after a fireball erupted in a shed blaze - shortly before emergency services arrived on the scene. Steve Wharton, a station manager with the Durham and Darlington Fire and Rescue Service, said firefighters were called to allotments at Kell Crescent, Sherburn Hill, near Durham, at 9.50pm.

He said: "It was reported as a house fire, but when firefighters got there they realised it was two large allotment sheds on fire.

"A gas cylinder had erupted in a fireball - thankfully before we arrived on the scene."

He added: "Our advice is for allotment holders is to remove unused gas cylinders or get rid of them.

"There is always the potential that if we turn up to an incident at an allotment a gas cylinder has heated up and could cause a fireball and endanger our crews.

"What initially turns out to be an allotment fire could be potentially something far more dangerous."

Mr Wharton said gas cylinders were designed not to explode but could erupt in a fireball if the valve blows off.

He said: "Some people do use Calor gas cylinders for heating in the winter, but now that it is summer there should be no need to keep gas cylinders in sheds."

He said acetylene cylinders could remain explosive for up to 24 hours after a fire and they should under no circumstance be stored in allotment sheds.

Mr Wharton said fire investigators were looking at possible links with an allotment fire reported at 10.05pm next to the Durham Fine Furniture in Sherburn Hill.

Anyone who may have noticed anything suspicious should contact 0845-60-60-365.