 In December 1977, President Giscard d'Estaing ordered the French Air Force to deploy in Mauritania and start bombing Polisario columns with napalm, after French civilian technicians were taken as hostages in a Polisario raid on the Zouerate iron ore mines, Mauritania's most precious economic asset (they were later released unharmed, although a French physician and his wife were killed during the attack).France used Jaguar combat aircraft from Dakar Airbase.The bombings were targeted in the rail route from the iron mines in Zouerat to the coast of Nouadibou, which were obstructed by Polisario.