At least 11 firefighting units from Khulna and Bagerhat are working to douse the fire.
Local people and workers of fire units said, the fire originated from a machine room of the mill at around 5:40pm.
Talking to BSS, Md Abdul Kadir, duty officer of the city's Noornagar Fire Service control room, said, on information, a total of 11 fire service units went to the spot to douse the blaze.
Any information about causalities could not be known immediately, he said, adding that firefighting activities were ongoing until filing the report around 8 p.m, reports BSS.
Causes of firefighting and quantity of damage to the mill also could not be known around 8 p.m., he added.