Fire fighters are battling to contain a huge blaze sparked by an explosion at an industrial estate today.
The fire broke out at 1pm after an explosion at Stiller's toiletries factory at the Aycliffe Industrial Estate in Newton Aycliffe, County Durham, police said.
A large police cordon has been set up surrounding the burning building and local schools have been advised to keep children indoors until the blaze is under control.
A Durham Police spokesman said: "Just after 1pm this afternoon there were reports of an explosion followed by a large fire at Stiller's factory, which makes toiletries.
"Fire crews are at the scene and a large police cordon is being placed around the scene.
"We are not aware of any casualties at this time.
"The current advice to residents and others in the immediate vicinity is to stay indoors, close all doors and windows and monitor local radio.
"Officers are contacting local schools to advise them to keep children indoors at this time. The schools will be advised when this position changes.
"We have no information as to the cause of the fire at this time."
The fire is being treated as a major emergency incident, Durham Police said.
The factory has been evacuated and people are leaving the area for their own safety.
"There are road closures in place around the site of the fire but main roads have not been affected," the police spokesman said.
"People are advised that there is a major emergency response to this incident so the roads surrounding Aycliffe Industrial Estate will be busy.
"People are asked to keep clear of the area until the incident is contained."
Investigators have begun work to determine the cause of the fire, he said.
Between 40 and 50 firefighters from County Durham and Darlington Fire and Rescue Service have been sent to tackle the blaze.
They are using a high ladder platform to fight the flames from the air, and ten fire engines are on the ground.
The smoke from the burning factory can be seen from five miles away.
A fire service spokesman said Newton Aycliffe residents heard a loud explosion before seeing the flames erupt.
He said: "People heard the bang before they saw the flames.
"We are not aware of any casualties yet but we have not had much information from on the ground; people are too busy fighting the fire.
"There is a lot of smoke and it can be seen from some distance away.
"We're telling people to stay in doors for the moment, because of the smoke, but this is standard practice when there's an incident of this kind at a factory. We are not aware of any toxicity."
The smoke plume from the fire is heading towards Darlington but is not believed to be toxic and is not causing any problems for traffic, police said.
Fire service experts said there was no risk of a second explosion, and have told schools it will be safe to allow children to leave at the normal time.
Assistant Chief Constable Michael Banks said: "This is a major incident and we are working with our colleagues in the fire and rescue service, civil contingencies unit, local authority, health and safety executive and other agencies to bring the fire under control and restore normality as soon as possible.
"Fortunately there are no reports of any casualties at this time.
"I'd like to thank local people for their patience and co-operation as we work to contain this situation."
He said it was too early to say whether or not the cause of the fire was suspicious.