The Nigerian Safety Investigation Bureau has opened an inquiry into a private aircraft that lost a door in mid-air shortly after taking off from Abuja.

The foreign-registered Challenger 604, operated by Triton Aviation, was heading to Lagos when the incident occurred.

The aircraft, with registration T7-SEI, departed Nnamdi Azikiwe International Airport at 16:12 UTC on Thursday. About three nautical miles from the airport and climbing through 3,500 feet, the crew issued a Mayday call after the door separated from the plane.

The jet returned safely to Abuja and landed on Runway 22 at 16:34 UTC. There were nine people on board — three crew members and six passengers — and all were unharmed. The Challenger 604 is registered in San Marino.

According to the bureau, the missing door has been recovered and secured at its wreckage hangar. Director-General Alex Badeh Jr confirmed that a full investigation is under way to determine the exact circumstances of the occurrence.

The incident triggered an emergency response at the Abuja airport, with fire, rescue and medical teams placed on standby for the aircraft’s return. The Nigerian Civil Aviation Authority earlier confirmed the event and noted that the probe falls under the NSIB’s responsibility. Further updates will be released as the investigation continues.