a third French soldier has been killed in fierce fighting with Islamist rebels in northern Mali, officials have said, but they couldn't confirm a report from Chad that its troops had killed the al-Qa'ida commander behind January's mass hostage-taking in Algeria.
A whirlwind seven-week campaign has driven al-Qa'ida-linked fighters who took over northern Mali last April into mountain and desert redoubts, where they are being hunted by hundreds of French, Chadian and Malian troops.
France's defence ministry said 26-year-old Corporal Cedric Charenton had been shot dead during an assault on an Islamist hideout in the desolate Adrar des Ifoghas mountains near Algeria.
French army spokesman Colonel Thierry Burkhard said some 15 Islamists were killed in some of the fiercest fighting during the campaign so far.
However, he said that he could not confirm Chad's claim that its troops had killed al-Qa'ida commander Mokhtar Belmokhtar (pictured) at a nearby camp in the remote Ametetai valley.
"We are facing a very fanatical adversary," Mr Burkhard said, noting the Islamists were armed with rocket and grenade-launchers as well as machine guns, AK-47 assault rifles and heavy weapons. "They are fighting without giving ground."
The death of Belmokhtar, nicknamed 'the uncatchable', has been reported several times in the past. The latest came a day after Chadian President Idriss Deby said Chadian forces had also killed Adelhamid Abou Zeid, al-Qa'ida's other senior field commander in the Sahara.
The killing of Belmokhtar and Abou Zeid, if confirmed, would eliminate al-Qa'ida's leadership in Mali and raise questions over the fate of seven French hostages thought to be held by the group in northern Mali.
Belmokhtar became one of the world's most wanted jihadis after masterminding the raid on the In Amenas gas plant in Algeria in which more than 60 people were killed, including dozens of foreign hostages.
Abou Zeid is regarded as one of al-Qai'da's most ruthless operators, responsible for the kidnapping of more than 20 Western hostages since 2008.
France and Mali said they could not confirm his death.