PARIS—French authorities are trying to figure out whether a man arrested in the West African nation of Mali who was en route to Islamist combatants is the same man charged in Paris with a terror-related offense, a judicial official said Thursday.

Al-Qaida in the Islamic Maghreb, or AQIM, is one of three extremist groups who have taken control of the northern half of Mali. The group is made up mainly of foreign fighters. The radical Islamists moved into northern Mali—an area the size of France—after a military coup in March overthrew Mali's democratically elected president.

Western and African leaders are now worried that northern Mali will destabilize Africa's entire Sahel region.

Mali authorities notified France this week of the arrest. French judicial officials are now trying to verify whether the man, who was traveling under an assumed name, is a French-Malian charged in 2010 in another case but released from jail last June, the official said.

The official was not authorized to speak publicly.

The suspected jihadist is being held in Bamako while French officials determine via fingerprints whether he is Ibrahim Aziz Ouattara. He told Mali officials he was trying to get near the ancient city of Timbuktu, where radicals have pillaged tombs of saints, the French official said.

Ouattara has a long history of trips to regions where Islamist radicals are active, including countries like Yemen and Somalia. French

authorities also linked him to a plot to kill the head of the Paris mosque, according to the official.

France, Mali's former colonial ruler, is pressing hard for an African military intervention against the Islamists that it and other allies promise to back with logistical support.