The Maharashtra Pollution Control Board (MPCB) has shut down four ready-mix concrete (RMC) plants in Mumbai and initiated action against 37 units, recovering penalties of Rs 1.87 crore amid stepped-up measures to curb air pollution, reported news agency PTI.

"Special flying squads will immediately begin inspections to verify whether prescribed conditions are being followed, and strict action, including closure, will be taken against violators," said M Devender Singh, member secretary, MPCB, referring to the action initiated against RMC plants contributing to air pollution, reported PTI.