From the end of March the men were allegedly not allowed to leave the mill in the northern city of Kano.
The men said they were threatened with sack by the managers of the Indian-owned mill, Popular Farms.
Policemen stormed the factory on Monday after obtaining a court injunction, arresting four managers and releasing the detained workers.
The Police in Kano have rescued over three hundred people locked in a rice-processing factory and forced to work throughout a coronavirus lockdown.
From the end of March the men were allegedly not allowed to leave the mill in the northern city of Kano.
The men said they were threatened with sack by the managers of the Indian-owned mill, Popular Farms.
Policemen stormed the factory on Monday after obtaining a court injunction, arresting four managers and releasing the detained workers.
