Hyderabad, July 9 -- An FIR has been registered after a hoax bomb threat prompted a huge security scare at Shaheed Bhagat Singh International Airport last week.

A note "bomb inside" was found on a tissue paper in the lavatory of an IndiGo flight that had come in from Hyderabad on July 5.

The note was discovered during a routine cleaning procedure after everyone had disembarked, according to officials. The plane was to proceed to Delhi when the message was found by ground staff, who promptly alerted the airline's security personnel.

The incident was brought to the notice of airport officials and the Punjab Police. A bomb disposal team, anti-sabotage unit, and officials from the Central Industrial Security Force (CISF) thoroughly searche...