Kanpur, Jan 8 (IANS): Kanpur authorities have ordered the "immediate shutdown" of 91 leather tanneries in the city that were offloading their waste in the Ganga river, causing widespread water pollution, an official said on Tuesday.

The crackdown comes days before the start of the Kumbh Mela in Prayagraj from January 14.

"The idea is to ensure that the Ganga remains non-polluted and that devotees who go to the biggest religious congregation get pure and clear water," the Uttar Pradesh Pollution Control Board (UPPCB) official told IANS.

Closure orders for the remaining 28 tanneries in the Chabilapurwa locality are likely to be issued later on Tuesday, sources said.

More than 15 tanneries functional in the neighbouring Unnao have already been closed for the period of Kumbh.

Some tanneries have been let off as they had treatment plants for their hazardous waste and are not passing off any water in the river.

Chief Minister Yogi Adityanath has ordered officials to ensure that waters of the Ganga was pure.