A handwritten bomb threat note was found aboard an IndiGo flight headed to Shillong, just before its scheduled departure, triggering a security emergency at the Netaji Subhas Chandra Bose International Airport in Kolkata on Saturday.

A crew member found a note in the lavatory of IndiGo flight 6E-7304, suggesting a potential explosive on board, said sources. The aircraft was immediately diverted to an isolation bay, away from the main terminal and other active taxiways, and passengers were disembarked from the aircraft.

“All passengers and crew have been safely evacuated. Standard Operating Procedures (SOPs) are currently being followed, which include a thorough sweep of the cabin and a re-screening of all checked and carry-on baggage,” an airport official said.

The incident led to a significant deployment of the Central Industrial Security Force (CISF), with security personnel being stationed around the isolation zone. Specialised airport vehicles, including a fire tender and ground staff in high-visibility vests, were also seen coordinating the operation.

The luggage has been offloaded onto the tarmac for specialised screening by dog squads and bomb disposal units.

Airport authorities have not yet confirmed if any suspicious items were found.