Huge plumes of smoke were seen from miles across town after a blaze at industrial estate in Kidderminster.
Videos on Twitter showed smoke driving up into the air above the Hoo Farm industrial estate in Kidderminster, Worcestershire.
One image from the scene showed a unit in tatters as flames tore through its roof.
The fire service is currently putting out the blaze at the site, which is thought to belong to MCD - a flooring distributor, the Kidderminster Shuttle reports.
The local fire department told The Mirror that 20 fire trucks were sent to tackle the inferno. There are thought to be around 80 firefighters at the scene.
Hereford and Worcester Fire and Rescue spokesman Richard Prine said: "20 fire engines heading to the Hoo Farm Industrial Estate in Kidderminster.
Have you been affected by the fire? Email webnews@mirror.co.uk.
"First engine to arrive said the building was around 30 per cent alight.
"Locals are being advised to avoid the area and to keep windows closed."
The cause of the fire is currently unknown.
Staff were evacuated by police from nearby units, Birmingham Live reports.
Chief fire officer Jon Pryce tweeted the service would be at the building for "the next few days".
Worker Sarah Edwards said: "I work across the road from there and saw lots of smoke outside my window and heavy fire.
"We've now been evacuated by the police."
Among the engines are two with aerial ladder platforms - which are used to fight fires in tall buildings.
The building is a 120m by 60m single-storey building. Thirty per cent of it was ravaged when the first engine arrived, he said.
He added that the incident was "evolving" and that updates would be given throughout the day.
In another image, the towering blaze could be seen billowing smoke and flames up into the sky behind a residential homes.
West Mercia cops told The Mirror they have not launched a criminal investigation in relation to the fire at present.
Worcestershire County Council Highways & Travel said roads around the estate area have been shut down.
They have also asked the public to refrain from visiting the area.
They wrote: "Stop/go traffic control on A449 roundabout as Police evacuate site."
