A cargo plane chartered by Democratic Republic of Congo's army crashed near the capital Kinshasa on Saturday, killing all 12 on board, the authorities said.

The Antonov transporter had just taken off from Kinshasa's Ndjili airport, heading for the eastern region of Kivu, where the army is fighting militia groups, an airport official told AFP, speaking on condition of anonymity.

The plane went down at N'sele, about 100 kilometres (60 miles) east of the city, the source said.

DRC Transport Minister Jose Makila, in a statement read on state television, said there had been a total of “12 crew members on board” but there were “no survivors.”

“An inquiry is underway to determine the likely cause of the accident,” he added.

AFP reporters saw that the country's Republican Guard had erected a barrier around the crash site, in an uninhabited area that formerly housed an agro-industrial complex. The plane, which had a Russian crew, was carrying “two vehicles and weapons” as well as military personnel, a source at the army's headquarters told AFP, also speaking on condition of anonymity.

Earlier accounts of how many people were onboard were contradictory. A source at the airport said there had been “several dozen” people on the plane, and the source at the army headquarters put the number at “between 20 and 30.”

But the airport's commander, Georges Tabora, told AFP that “there were no passengers onboard.” “There were only crew members because it's a cargo plane,” he said, without saying how many were onboard, or their nationality.

Army spokesmen could not be reached for comment.

A witness at the crash site told AFP he had seen the plane “falling” out the sky shortly before 9:00am but said there was no sign of any smoke coming from the aircraft. But another witness, an army lieutenant, said the aircraft caught fire in mid-air before crashing and that there was a series of explosions on the ground.

Smoke could still be seen rising from the wreckage hours after the crash, though AFP journalists were prohibited from taking photos or video of the scene by soldiers on the perimeter, guns at the ready.

A passenger who had been unable to board the flight at Ndjili said the plane's destination was Bukavu, capital of the sub-region of Sud-Kivu, which lies on the frontier with Rwanda. Fighting broke out there on September 24, and was followed on Thursday by clashes in Sud-Kivu's second largest city, Uvira, which is on the border with Burundi.

At least three transport planes have crashed in the DRC since 2000. As many as 200 people died when they were sucked out of a Russian-made Ilyushin 76 plane after a door fell off the aircraft as it headed from Kinshasa to Lubumbashi in the southeast in May 2003.