Mumbai and Navi Mumbai were placed on alert after threatening emails reportedly targeted a school, Mumbai Mayor Ritu Tawde, Punjabi singer Diljit Dosanjh and Bollywood actor Amitabh Bachchan.. A threatening email sent to Mumbai Mayor Ritu Tawde reportedly named Amitabh Bachchan’s Juhu home and Diljit Dosanjh’s November 27 concert, prompting increased security across the city.