GAO, Mali French troops clashed with Islamist extremists firing rocket launchers outside the north Malian city of Gao, France's defense minister said Wednesday.
Jean-Yves Le Drian also said there have been "several hundred" Jihadist fighters killed and "large" destruction of weapons, giving the first indication of the scope of the combat in an interview Tuesday on France's BFM TV.
"It's a real war ... when we go outside of the center of cities that have been taken, we meet residual jihadists," he said Wednesday on Europe-1 radio.
Northern cities Gao and Timbuktu have been held by French-led forces since late January, and Tuesday's clashes highlight complications for the intervention.
Le Drian said "We discover preparations for a true terrorist sanctuary."
French President Francois Hollande said, meanwhile, that France might start pulling its troops out of Mali as soon as the end of March.
Government spokeswoman Najat Vallaud-Belkacem said that at a Cabinet meeting Wednesday, President Hollande "confirmed that if all goes as planned, by the end of March the number of French troops engaged in Mali can begin to diminish."
Vallaud-Belkacem said the pullout would depend on an increase in the deployment of African forces, who are meant to take over the international effort to secure Mali and help its weak army keep the peace.
Also Wednesday, Malian troops found a cache of industrial strength-explosives, weapons manuals and makeshift laboratories for making improvised explosive devices like roadside bombs in Gao on Wednesday.
The stash of materials included NITRAM 5, which had been hidden inside rice bags that were dumped in a small square with other garbage from the town. The discovery was made after a local official alerted the soldiers to the scene.
France launched a swift military intervention Jan. 11 against Islamic extremists who had taken over northern Mali, imposing harsh Shariah law, and started pushing toward the capital. A U.N.-authorized African force is starting to take over from French forces in cities seized at the outset of the intervention.
A secular rebel movement fighting for a nation for Mali's minority Tuareg nomads claims it is holding several smaller northern towns, including the strategically located city of Kidal, on the road to Algeria. French and Chadian troops entered the city Tuesday.
Moussa Ag Assarid of the National Movement for the Liberation of Azawad said their fighters also are holding the northeastern towns of Tessalit, Menaka, Aguelhok and Tinzawatten, as well as Kidal. Azawad is what the Tuaregs call their would-be country
It was not immediately possible to verify the claims.
Trouble began in Mali, once a stable democracy in West Africa, with the latest in a series of Tuareg rebellions in the north last year. Poorly armed and demoralized Malian soldiers fled before their advance, then staged a coup in the faraway capital, Bamako. NMLA fighters joined up with Islamist militants linked to al Qaeda and quickly overran all main northern cities.
But the secular fighters fell out with the Islamic extremists when they started imposing Shariah law, including amputating limbs, public whipping and stoning people to death, and their rebellion was hijacked.
As the extremists have fled the French bombing campaign, it appears the NMLA fighters have moved back in.
They have said they are willing to work with the French forces but not Malian troops they accuse of committing reprisals against the lighter-skinned Tuaregs and Arabs.
France and other Western governments fear the region could become a haven for international terrorists.
Le Drian said French aircraft are continuing air strikes every night on suspected militant arms depots and mine-making sites.