(BSS/AFP) - An African Union helicopter crashed Wednesday at the airport in the Somali capital Mogadishu, killing at least three people and injuring several civilians when munitions onboard detonated, officials and witnesses told AFP.

The aircraft was part of the African Union Support and Stabilization Mission in Somalia (AUSSOM), tasked with fighting the Al-Shabaab militant group.

The helicopter, operated by the Ugandan contingent, "crash-landed" at around 7:30 am (0430 GMT) at Mogadishu`s Aden Abdulle International Airport after departing from Baledogle military airbase, AUSSOM said.

"There were several people recovered from the scene of the crash, three of them were already dead, and they were carried in stretchers," police officer Abdi Ali told AFP.

The helicopter was conducting a routine combat escort mission, according to the Ugandan military.

"The impact triggered a detonation of onboard munitions, causing significant damage to nearby structures and injuring three civilians," it said in a statement.

It said the pilot, co-pilot, and flight engineer survived the crash, "but sustained serious injuries and severe burns".

They and the three civilians were taken to hospital for treatment, the statement said.

Witness Mohamed Yare, who was in the airport at the time, told AFP that some of those onboard had died "but I could not say how many".

"There were ambulances and firefighting trucks rushing to the scene, and there was smoke and fire," he said.

Somalia`s civil aviation authorities told reporters investigations were ongoing into the cause of the crash.

Ahmed Moalim Hassan, director-general of the Somali Civil Aviation Authority, said the airport remained operational despite debris on the runway.

Unverified clips and images shared online showed a plume of black smoke over the city.

The US embassy in Mogadishu expressed its "deepest condolences to the families of the brave warriors" in a post on X.

The AUSSOM mission faces funding difficulties, even as fears of an Al-Shabaab resurgence are stoked by attacks in the Horn of Africa nation.