Hundreds of Islamist fighters from Algeria to Sudan are reported headed to northern Mali as jihadists linked to al-Qaida in the Sahel region prepare to repulse an offensive by regional armies aided by France and, more discreetly, the United States.

"The Sahel is becoming a sanctuary for terrorism," declared French Defense Minister Jean-Yves Le Drian. "The safety of Europe and of France is at stake here."

It's feared that major military intervention, most likely by forces of the 15-member Economic Community of West African States, is likely to trigger heavy fighting. That would widen political turmoil that has swept the region since pro-democracy uprisings erupted in Tunisia in January 2011 and spread along the southern shore of the Mediterranean.

This could drag in regional heavyweights like Algeria, the main military power in North Africa, and even France and the United States, which has been steadily widening its global war against al-Qaida and its offshoots.

U.S. Special Forces units have been deployed across the region, particularly since the Sept. 11 assassination of U.S. Ambassador to Libya Christopher Stevens and other Americans in Benghazi, Libya.

France, the former colonial power in much of north and central Africa, is reported to be deploying unmanned aerial surveillance drones to the region.

Paris says northern Mali is increasingly becoming a jihadist stronghold, in the way that Afghanistan became one for al-Qaida in the late 1990s and from where it launched the 9/11 attacks on the United States.

"AQIM has established resources in the north -- including airstrips, military based, arms dumps and training camps -- that alarm Western states," observed the Financial Times.

"A territory twice the size of France ... is totally controlled by terrorist groups and it's a magnet for all the bad guys in the region," a senior French official said.

"They're attracting youngsters from all over the world. It's a cancer."

France has more at stake than most states outside North Africa. Al-Qaida in the Islamic Maghreb, the main jihadist group in the desert region, has killed French captives in the past. AQIM currently holds six French hostages and threatens to execute them if an attack is launched.

AQIM has France is its cross hairs because of its colonial past and the massive investments it holds across North Africa.

Regional security sources say there's "credible evidence" the jihadists are plotting attacks following abortive bombings of French embassies in Mali and neighboring Mauritania, where French commandos have mounted periodic joint attacks with local troops against AQIM bases.

France's new president, Francois Hollande, says there's a real danger of terrorist attacks in France and is pushing hard for a military offensive against AQIM in northern Mali.

French sources say Paris, which has military and air forces deployed in its former African colonies, wants the European Union to train 3,000 troops from the Malian government in the south of the country.

On Oct. 12, the U.N. Security Council approved a French-led resolution aimed at resolving the Mali crisis and gave ECOWAS 45 days to draw up an intervention plan.

But African armies are in bad shape, with little training, poor leadership and obsolete equipment.

African interventions in recent years achieved little, although the recent success of troops from Kenya, Ethiopia, Burundi and Uganda against Islamists in Somalia indicate what could be achieved.

The U.S. administration remains less enthusiastic about a full-blown military campaign but it's under pressure to avenge the Benghazi murders.

It may be significant that U.S. Army Gen. David Rodriguez, an Afghanistan veteran who helped plan the U.S. surge offensive there, has been nominated as the next head of the U.S. Africa Command, which oversees American security operations on the continent.

Meantime, the United States has stepped up intelligence-gathering in the region through satellite and spy drone flights to track jihadist positions, security sources said.

The jihadists seized northern Mali in March, driving out Tuareg secessionists, their erstwhile allies, who had briefly established their own state in the regional fallout from the 2011 Libyan civil war.

Since then, AQIM and its smaller allies, Ansar Dine, or Defenders of the Faith, and the more recent Movement for Oneness and Jihad in West Africa, have enforced harsh Islamic law with executions and amputations.