A small Nigerian air force passenger plane crashed just outside Abuja airport after reporting engine failure on Sunday, killing all seven people on board, the air force said.

The plane, a Beechcraft King Air 350i, was on its way to Minna, Niger state, 110 kilometres (68 miles) northwest of the capital, air force spokesman Ibikunle Daramola said in a statement.

The aircraft “crashed while returning to the Abuja Airport after reporting engine failure”, said Daramola. “First responders are at the scene. Sadly, all seven personnel on board died in the crash.”

Chief of air force has ordered an investigation into the accident, Daramola said.

President Muhammadu Buhari in a statement sent his condolences to the air force and families of the victims, saying he was “deeply saddened by the fatal crash”.

In scrubland just outside the airport perimeter, dozens of military and airport officials picked through the charred remnants of the fuselage as fire engines and ambulances stood by.

The smell of burning chemicals lingered in the air but no fire or smoke were visible. Onlookers watched the rescue efforts from behind a cordon.

“As he (the plane’s pilot) was going down, he struggled to go back to the airport, at the end he just crashed,” said Alaba Lawal, who said she witnessed the accident.

“I just saw the whole thing explode, fire and smoke together ... When I got there I saw dead bodies on the ground.”

The Beechcraft King Air 350i is a twin-propeller aircraft made by Textron Aviation, a unit of the U.S.-based Textron Inc conglomerate. The model was first released around 2009.

The company said in a statement that it had been notified of the accident, which it said is being investigated by Nigeria’s Aircraft Investigation Bureau and the U.S. National Transportation Safety Board.

“As a party to the investigation, the company is prohibited by NTSB regulation from divulging any information about the accident or investigation,” the company said.

The NAF listed the deceased officers as:

• Haruna Gadzama, flight lieutenant who was the captain
• Henry Piyo, co-pilot and flight lieutenant
• Micheal Okpara, a flying officer and airborne tactical observation system (ATOS) specialist
• Bassey Etim, a warrant officer (ATOS Specialist)
• Olasunkanmi Olawunmi, a flight sergeant (ATOS Specialist)
• Ugochukwu Oluka, a sergeant (ATOS Specialist)
• Adewale Johnson, an aircraftman (onboard technician)

Reuters