Four people are believed to be trapped amid a “raging” fire at a wood treatment works near Macclesfield following several explosions.

Cheshire Fire and Rescue Service said it was called to reports of an explosion at a wood mill in Tunstall Road at about 9.10am.

Norman, who did not wish to give his full name, told BBC Radio Manchester: “We live more than half a mile away and yet the shockwave was so much that I actually thought something had hit the house”. I can’t imagine how the houses nearer the site took it. Police said there might be chemicals at the plant.

“We looked over and there were massive plumes of flames”.

He said it was too soon to speculate on the cause of the blaze.

A total of eight crews are at the site, with two appliances from Leek.

Mr Hancock said the last explosion at the site happened at about 10.15am. She was given pain relief, her burns carefully dressed and she was immobilised before being airlifted to Queen Elizabeth Hospital Birmingham by the Midlands Air Ambulance from Cosford for further specialist treatment; the MERIT trauma doctor continued treatment en route. There is a safety cordon around the scene.

Cheshire Police tweeted confirming there have been further explosions: “We continue to deal with the Bosley Incident – there have been a further two explosions and believe there are 4 people trapped”.

“It is also advised to avoid the area while we deal with this incident”.

Local residents have been asked to keep windows shut and to stay indoors.

Chief Inspector Paul Carroll, from Cheshire Police, added: “There is now a lot of smoke emanating from the building and it is advised that residents living in the area should close their doors and windows”.

Three men and one woman are said to be unaccounted for.

Cheshire East Council has warned of “multiple injuries” and said as many as five people could be trapped in the building, which is on fire. “It’s a small community and there were 50 jobs there”.

Some have posted photos on Twitter of th aftermath of the blast. They are clearly in a state of shock.

“It’s absolutely vital they get all the support they need”.

“Emergency services are now at the scene, and have declared this a major incident”.