A fourth 250-kg bomb was found at a construction site of the third terminal at Hazrat Shahjalal International Airport (HSIA) in the capital Dhaka on Monday.
The bomb was a General Purpose (GP) bomb, Mohamamd Rezaul Karim Shammi Assistant Director of the ISPR, said in a statement.
It was found when workers were digging a hole for piling at the construction site on Monday.
On information, Air Force's Bomb Disposal Unit went to the spot and identified it as a GP bomb.
The authorities Air Force Base - Bangabandhu's Bomb Disposal Unit, later confirmed it was a bomb and defused it.
Experts opined that the bomb was dropped during the Liberation War in 1971.
The bomb was taken to safe place with the necessary precaution.
Earlier another three two cylinder-like bombs of same weight were found at the construction site of the third terminal.