French and Malian troops clashed with Islamist rebels near the large town of Gao, Paris said on Wednesday after reporting that hundreds of insurgents had been killed in a "real war" to reclaim northern Mali.
French Defence Minister Jean-Yves Le Drian said the extremist rebels, who have been driven from key strongholds which they had controlled in northern Mali for 10 months, struck back at troops with rocket fire on Tuesday.
"There were clashes yesterday around Gao," Le Drian said on Europe 1 radio. "Once our troops, supported by Malian forces, started patrols around the towns that we have taken, they met residual jihadist groups who are still fighting.
"We will go after them. We are securing the towns we have been able to take along with the Malian forces. The jihadists around Gao were using rockets yesterday."
The confirmation of clashes comes after one of the militant groups, the Movement for Oneness and Jihad in West Africa (MUJAO), said it had attacked military positions in Gao, the largest city in the north.
"The combat isn't over. The attacks are going to continue," MUJAO's Abou Dardar told AFP.
The Malian army arrested two young men in Gao's market Wednesday who were brandishing two grenades and a pistol, though it was unclear "whether they planned to commit an attack or wanted to use the weapons for robbery", a police spokesman said.
On Tuesday, Le Drian said "several hundred" Al Qaeda-linked militants had been killed by French air strikes as well as "direct combat" in the key central and northern towns of Konna and Gao.
"This is a real war with significant losses but I'm not going to get into an accounting exercise," he said Wednesday when asked about the toll.
France's sole fatality so far has been a helicopter pilot killed at the start of the military operation 27 days ago.
Mali said 11 of its troops were killed and 60 wounded after the battle at Konna last month but has not since released a new death toll.
France launched its surprise intervention in the former French colony on January 11 as a triad of Islamist groups that had seized control of the north in the aftermath of a military coup pushed south toward the capital.
Nearly 4,000 French troops have deployed, a number that will not be increased, Le Drian said. The force matches the size of the French deployment in Afghanistan at its height in 2010.
With Paris keen to pass the baton to some 8,000 African troops pledged for Mali, French Foreign Minister Laurent Fabius said soldiers would begin withdrawing "in March, if all goes as planned".
Hollande confirms March withdrawal
President Francois Hollande confirmed that timeline, with a government spokeswoman telling journalists: "As far as Mali is concerned, the president confirmed this morning that if everything goes to plan, the number of French troops in Mali will begin to fall from the month of March."
Hollande, whose surprise decision to intervene in Mali won him a hero's welcome there on Saturday, had said during his whirlwind visit that France will stay as long as it takes.
The Islamists have put up little resistance, many of them fleeing to the Adrar des Ifoghas massif around Kidal, a craggy mountain landscape honeycombed with caves where they are believed to be holding seven French hostages.
Kidal, the last key bastion of the Islamists, is now under control of French forces and some 1,800 Chadian troops, but fighter jets continue to pound the region around the remote desert outpost.
With the fighters hidden in familiar terrain, the French military says it plans to flush them out by cutting them off from supplies.
Meanwhile a Tuareg separatist rebel group that kickstarted Mali's descent into chaos with a rebellion for independence last year said it is working with France against "terrorists" in the region.
The Azawad National Liberation Movement (MNLA) linked up with the radical Islamists in its bid to secure independence for the desert nomad Tuareg people, who have long felt marginalised by Mali's government.
But after being chased from their strongholds by the extremists, they have voiced a willingness to negotiate since France intervened.
The MNLA said on Wednesday it had retaken the town of Menaka, 80 kilometres (50 miles) from the Niger border, which Nigerien troops had taken from militant occupiers but then left as they continued their advance.
Le Drian said France had "functional relations" with the group in Kidal but that fighting terrorists alongside them was "not our objective."