Four Russian military cargo planes from Benghazi have landed at Gao airport since Monday, a source told the French website Monde Afrique on Friday.
One witness told the French website that the planes carried military equipment and men.
This comes after a Russian Ilyushin Il-76 crashed at the end of the runway near Gao airport with heavy cargo on board on September 23.
Gao Airport is the largest in northern Mali and served as a rear base for the French army before its departure.
The Russian-Libyan axis has been strengthened in recent weeks after President Vladimir Putin received Marshal Khalifa Haftar in Moscow on Sept. 27. The trip was preceded by two Russian missions to Benghazi to meet with Haftar, on September 17 and August 22.