Windows around the market place were shattered by the blast

Wreckage and broken glass was strewn across the town centre of Wolsingham, near Bishop Auckland on Saturday.

The 33-year-old driver, who lived locally and worked as a welder on the outskirts of Durham, was in the van when oxy-acetylene cylinders exploded.

A Durham Police spokesman said the area was still "very hazardous".

We have to systematically check each piece of debris at each location, and these pieces of the jigsaw puzzle will then come together Steve Wharton, County Durham and Darlington Fire and Rescue

It is not yet known what caused the blast but the force said there did not appear to be any suspicious circumstances.

Fire crews worked through the night to make the area safe, but a gas cylinder blown clear of the van by the explosion was still at the scene on Sunday.

The cylinder has to be cooled for no less than 24 hours before it can be removed, according to the fire service.

Steve Wharton from County Durham and Darlington Fire and Rescue said: "We can't start investigations while the threat of further explosion is still there so investigators have to stand off at safe distance until declared safe."

Homes evacuated

He added: "Then we have to systematically check each piece of debris at each location, and these pieces of the jigsaw puzzle will then come together."

Several residents who live close to the market place were forced to move out of their homes after the explosion, but most of the buildings nearby are commercial properties.

Windows were blown out by the force of the blast, but the extent of any structural damage is still unknown.

Fire crews are sifting through debris scattered across the town centre

Catherine Dipper, whose son was showered with glass from his bedroom window, but otherwise unhurt, was among those evacuated.

Speaking on Sunday, she said: "We've been asking when we will get to go back, but we can't until the gas cylinder has been removed.

"We went down there this morning and it's still there, so we're just waiting to see when we will be allowed back."

A Durham Police spokesman described the incident, at about 0700 BST on Saturday as "tragic", but said it could have been much worse had it happened later in the day.

No-one else was hurt in the explosion, on the town's Front Street. Traffic diversions remain in place and motorists are advised to avoid the area.

Two public help lines containing road closure details and related information have been set up.

The numbers are 01325 742549 and 742565.