Traces of cocaine among the remains of a cargo plane recently discovered in West Africa suggest that large aircraft are increasingly being used to smuggle drugs and even weapons to the region, possibly benefiting terrorists, the United Nation’s anti-crime chief said recently.

The burned debris of a Boeing cargo plane was discovered in early November in the Gao region of Mali, said Antonio Maria Costa, head of the Vienna-based U.N. Office on Drugs and Crime. It is assumed to have landed on a clandestine landing strip and either failed to take off again or was destroyed on purpose, he said, adding that “ample traces of cocaine” were found on board.

While the origins of the plane are still unclear, Venezuelan and Colombian air traffic controllers in late October reported “strange behavior” from a Boeing cargo plane that eventually went missing in southwest Venezuela, Costa said. Authorities in Mali, Interpol and the United Nations are investigating, he added.