Police said Thursday that ten workers were killed and two others remained missing after a fire swept through a mushroom processing factory in Cheongdo, North Gyeongsang Province Wednesday afternoon.

A total of 162 workers were inside the factory when the fire erupted. All but 12 have been confirmed to be safe.

Authorities said that on Wednesday, firefighters found 10 charred bodies in front of a staircase leading to the third floor of the three-story building.

Police said firefighters were searching for the two missing person, but they were feared to be dead.

Witnesses said that most workers escaped from the factory through the building's only window on the ground floor as sawdust and other flammable materials caused the fire to spread rapidly.

More than 20 fire engines and 160 firefighters rushed to the scene and brought the blaze under control four hours later.

Police suspect the fire was ignited by welders who were dismantling steel structures in the building. They detained one of the welders, identified only as Kim, 31, for questioning.