Bangladesh's top civil aviation officials on Monday said that they are probing how a "hijacker" was able to bypass airport security with a "toy pistol" and board a Dubai-bound plane.
"We are still trying to understand the situation," State Minister for Civil Aviation Mahbub Ali told reporters.
The minister also said that authorities are yet to ascertain whether the suspected hijacker was carrying a "toy gun".
"We have checked all our airport security scanning system. We didn't find any flaw in the security system there," he said.
The flight, en route Dubai from Dhaka via Chattogram, with 148 passengers and crews on board was hijacked soon after it left Dhaka Sunday.
The pilot contacted Chattogram's Shah Amanat International Airport and made an emergency landing. Passengers were then evacuated safely from the plane.
After two tense hours, a commando operation put an end to the hijacking in about eight minutes. Army and air force officials said a suspect holding a pistol had been killed.
Asked how the weapon had gotten on board the plane, Civil Aviation Secretary Mohibul Haque said: "We do not know whether it was a weapon. We do not know if it was a toy pistol. The full details will be available in the investigation report."