A COLUMN of thick black smoke was visible for more than 30 miles last night after a fierce blaze gutted a plastics factory.

Neighbouring factories on the Aycliffe Trading Estate at Newton Aycliffe, near Darlington, were evacuated as firefighters fought to control the flames at North East Packaging.

Their task was made even more hazardous by a series of small explosions - thought to be oxygen and gas bottles used in the manufacturing process.

As a huge cloud of billowing smoke drifted towards the town, police and firefighters advised worried householders to remain inside and keep their doors and windows shut as a precaution.

Seven fire crews attended the incident along with two aerial ladders and firefighters are expected to remain at the scene until this morning as the blaze is allowed to burn itself out under controlled conditions.

Hundreds of people headed to the estate to watch the drama - some coming from as far afield as Stockton, where the smoke was plainly visible.

Twenty police officers from Aycliffe and Spennymoor were drafted in to help with the evacuation and throw a cordon around the area.

The 40 workers employed by North East Packaging left the 600 square metre unit at 4.30pm followed by the management, who locked up at 5pm.

Minutes later a member of the public raised the alarm - reporting that the roof of the single-storey building was ablaze.

Both police and fire brigade investigators will examine the scene over the next few days to determine how the blaze started - but early indications are that it is not suspicious.

Inspector Simon Orton of Newton Aycliffe police said: "Our first concern was the safety of employees at the site and surrounding units. "Once we knew they were safe, the fire brigade turned their attention to hosing the building down from the outside."

Callum Jones, 23, who works at a neighbouring factory, said: "We came out about 5.30pm and there was thick black smoke which seemed to get worse over the next two hours."

One onlooker said: "I can't believe how many people have come down to look at the fire. Once you get here you can see why, the flames are everywhere."