Two workmen were taken to hospital following a fire at a factory.
Emergency services were called to a roofing products mill in Littleborough, Greater Manchester, shortly before 1pm today to reports of an explosion.
Fire crews from Littleborough and Rochdale attended and found a number of silos of solvent ablaze before they later brought the blaze under control.
A large plume of smoke surrounded the scene in Calderbrook Road and a number of houses in the surrounding area were evacuated as a precaution.
People were advised to keep their windows and doors closed to reduce breathing in the fumes.
One man was treated for burns to his arm while the other was contaminated with bitumen, police said.
Tony Lander, of Greater Manchester Fire and Rescue Service, said: "We are dealing with a fire involving a range of buildings, including a silo. There are bitumen tanks and liquefied petroleum gases (LPG) and various other chemicals involved.
"The building in total measures about 100 metres by 100 metres and there's a thick plume of black smoke going way up into the atmosphere and dissipating over the moors.
"We are using foam jets on the silos and have brought the fire under control so it's now almost non-existent."