A military aircraft burst into flames moments after landing at the international airport in Somali capital Mogadishu on Friday, sending a thick plume of black smoke into the sky, airport staff and witnesses said.
Small blasts could be heard from the stricken plane. Airport workers said they believed they were caused by exploding ammunition.
"We hear explosions as it burns. It is burning like hell. It is sure it will end up in ash," one security source at the airport told Reuters.
The source said the blaze was so intense firefighting crews were unable to tackle the blaze.
There was no immediate word on the crew and it was not clear where the military aircraft was flying from.
Military aircraft regularly land at the city's airport, which also serves as the headquarters for an African Union force battling al Qaeda-linked Islamist militants.
The plane belonged to Ethiopia and was carrying ammunition, two security sources said.
"It was an Ethiopian cargo plane with ammunition on board," said one security source, on condition of anonymity. At least one of the five crew members had died, he said.
Ethiopian soldiers are supporting the Somali government's fight against Islamist al Shabaab rebels, although they are not part of the African Union peacekeeping mission.