Two grenades were recovered from inside a garden beside the main entrance of Shah Makhdum Airport in Rajshahi on Tuesday.
A passerby spotted the grenades around 11am and informed police.
Additional Deputy Commissioner (Media) of Rajshahi Metropolitan Police Md Gaziur Rahman said police rushed to the spot after receiving information about two grenade-like objects lying beside the main gate.
The grenades were defused with the assistance of the bomb disposal unit.
"An investigation is underway to determine who left the grenades there and for what purpose," he said.
As Power and Energy Minister Iqbal Hasan Mahmood Tuku arrived at the airport on a flight at the same time he was escorted out through the rear gate as a security precaution.
Upon receiving the information, airport authorities and members of the Armed Police Battalion (APBn) immediately closed the entrance as a precautionary measure.
The move triggered panic among passengers arriving at the airport.
An alternative gate near the airport mosque was subsequently opened for passengers to enter and leave the premises.