"It has gone to the Canaries," a source close to the Mauritanian presidency said. The head of the Mauritanian state news agency said the aircraft had already touched down.
The hijackers reportedly wanted the aircraft to travel to Paris.
The jet was hijacked during an internal flight from the capital Nouakchott to the northern port of Nouadhibou.
The aircraft had been scheduled to fly on from Nouadhibou to the Spanish Canary Islands.
Police said the jet was initially diverted to Dakhla in Western Sahara for refuelling.