EMPLOYEES of a North-East bakery chain have been told their jobs are safe, but they may have to wait a month before returning to work after a blaze destroyed their headquarters on Sunday.

Nearly 700 people who work for Peter's Cathedral Bakery will still be paid.

Its stores are closed for the forseeable future but a production unit in Peterlee is expected to be up and running within four weeks.

The inferno that engulfed the building at the Dragonville Industrial Estate, in Durham, spewed out an enormous cloud of smoke which caused traffic chaos on the A1(M) and could be seen up to 20 miles away. Flames leapt up to 30ft in the air.

Police with loudhailers warned nearby residents to remain indoors and keep their windows closed.

At its height, up to 80 firefighters in 12 appliances were at the scene.

Midweek firefighters were still putting out 'hot spots' and said the entire building was ruined and remains dangerous.

On Wednesday forensic officers and detectives from Durham Constabulary teamed up with firemen who tackled the blaze to start the investigation into how it began.

Until now the site has been too dangerous to access because of hidden fires and crumbling walls but it will be made safe for the joint investigation teams.

Ian Doherty, of Durham and Darlington Fire and Rescue Service, said plastic pallets and cooking oil had probably fuelled the fire along with a series of gas fires that started once the blaze had taken hold.

He said the brigade had to wait almost five hours for the mains supply to be turned off so the fires could be extinguished in case it caused a major explosion.

Fifty people were evacuated when fire broke out at 4.30pm on Sunday. There were no reports of any casualties.

Managing director Richard Knowles said: "Thankfully, all employees were safely evacuated prior to the fire fully taking hold.

"This devastating blow to the business comes at a period during which the company is undergoing an extensive rebranding and refurbishment programme."

Prior to the building being destroyed, the bakery had submitted an application to build a new production hall and despatch area and office, creating jobs for 30 people.

The company has already indicated it would like to remain on Dragonville Industrial Estate as it has historic ties with the city and enjoys good road links to its 71 bakery outlets across the North-East.

Durham City Council planning officer Stuart Mills said he was waiting to hear from the firm to see what it plans to do. He said: "Until we hear from them we will proceed as normal but we don't know whether they want us to because they don't have the building to extend any more.

"It is likely that they will have to put in an application to rebuild. This is an application that will be difficult to deal with."

Allied Bakers Union spokesman Pat Paterson moved to reassure workers and customers of the bakers, which has been in Durham since 1966, that stores across the region would be open for business again soon. He said: "We have premises in Peterlee that will be up and running in about four weeks, so hopefully everybody will be re-employed.

"The management and all the rest of the team are working like hell to get the place up and running again, so I would like to say to all our customers to stick with us because we will be back."

In December, the firm was forced to suspend production after a fire gutted the firm's dispatch area.