New Delhi, Aug 12 - A Kolkata-bound IndiGo flight with 126 passengers on board was grounded at the Delhi airport Wednesday after a bomb threat call.

The Delhi-Kolkata flight (No 203) was grounded after a call centre of IndiGo received an anonymous call by 3.30 p.m. that a bomb has been placed in the aircraft, an airport official said.

All passengers were de-planed immediately and the aircraft was taken to a remote bay for checking by the airport bomb disposal squad.

'Nothing suspicious was found in the aircraft,' said the official.

The threat assessment panel was now looking into the issue, he added. 'The police are trying to track the caller but they are yet to get a lead.'