Ten firefighting units took nearly two hours to douse the fire that began around noon at the Hazrat Shahjalal International Airport, the country's main aviation facility.
The airport has resumed normal flight operations.
"We have resumed normal operations of the airport at 4 PM as the fire was completely doused," Civil Aviation Authority spokesman Rezaul Karim told PTI.
Authorities ordered an inter-departmental investigation by a committee comprising fire service, civil aviation and police officials to find out the cause behind the incident.
"The three-member committee has been asked to submit its findings in the next seven working days," a civil aviation ministry spokesman said.
He said that the fire did not hamper the scheduled arrival and departure of flights.
Officials said the fire originally broke out at the Air India office on the second floor of the airport's Terminal 1 and spread in the adjacent offices including the one of Qatar Airways raising a security alarm.
"The airport's internal fire-fighting unit doused the fire within a short time but 10 fire fighting units from the neighbourhood rushed to the scene," an airport official said.
Initially, electricity supply to the airport was cut off.
Employees and passengers evacuated from the various floors have reported seeing smoke inside the building.
TV footages showed that the elite anti-crime Rapid Action Battalion and special Armed Police Battalion laid a siege around the airport blocking its entry points as the fire fighters made hectic efforts to douse the fire evacuating passengers and non-essential staff.
The display screen of the airport's auto fire detector showed the text - "Fire on Air India floor" as soon as the fire alarm went off.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)