Sniffer dogs have indicated that the bag could be containing highly explosive substance, the top officer confirmed, following which due measures have been taken to ascertain the nature of the danger contained in the bag.

"The bag has been removed from the spot and put in a coolant, and it will stay there for the next 24 hours before the team checks its content. The CCTV footage is being checked to identify the owner," said CISF spokesperson, Assistant Inspector General Hemendra Singh.

The bag was first spotted by a CISF jawan V.K.Singh, who immediately put everyone on alert. After a special sniffer dog, Guide, signalled the bag being suspicious, all the top officials and related agencies were alerted.

A source in the CISF said the black colour bag was found near the pillar no. 4 at the arrival area of the airport terminal.