The Brihanmumbai Municipal Corporation (BMC) imposed GRAP stage-4 restrictions in Mumbai from Monday amidst deteriorating air quality in the city. "In all the areas of Mumbai where AQI index surpasses 200 mark, we'll be stopping work at all construction sites under GRAP-IV norms," BMC chief Bhushan Gagrani said. Construction activities in Borivali East and Byculla have been immediately halted.