A police official says that four workers at the Kano Tans Leather Factory in Nigeria's north drowned while removing industrial waste in the company's sewage treatment plant.
The deaths triggered protests by factory workers in the Challawa Industrial area of the northern city.
Kano state police spokesman, Assistant Superintendent of Police Musa Magaji Majiya said the four bodies were taken to the city's Murtala Muhammed Hospital and pronounced dead Thursday.
The state's environment commissioner, Alhaji Abdullahi Abbas Sanusi, said the state government will take more measures to compel the leather industries to install modern technology to deal with industrial waste.