Authorities in Mumbai were placed on high alert on Thursday morning after an email threatened bomb blasts at multiple locations across the city, including the airport, the Mayor's office, megastar Amitabh Bachchan's bungalow 'Jalsa' and a Punjab National Bank (PNB) branch, an official said.

The official further informed that the email was sent at 10.52 am from an account identified as reduak079 gmail.com. It was addressed to the PNB's Mumbai Zonal Office, the Local Crime Branch (LCB) at Cuffe Parade and the bank's Zaveri Bazar branch in south Mumbai, news agency PTI reported.