Mumbai Police received an email at the BMC office on October 23, warning of a possible suicide attack at singer Diljit Dosanjh's upcoming Mumbai concert and threatening actor Amitabh Bachchan. The sender claimed Bachchan's house would be targeted with a grenade on October 31, and mentioned "khoon ka badla". The email's subject line read, "Mumbai Bombay Bolega Khalistan Zindabad".