Two French soldiers died in Mali on Saturday when their armoured vehicle was hit by an improvised explosive device.
The two were in the eastern region of Menaka collecting intelligence, the French presidency has said.
It comes days after three other French soldiers died in a similar way.
France has 5,100 troops in the Sahel region which has been a front line in the war against Islamist militancy for almost a decade.
The French first intervened in the Sahel region - a semi-arid stretch of land just south of the Sahara Desert which includes Mali, Chad, Niger, Burkina Faso and Mauritania - in 2013.
These latest deaths brought to 50 the number of French soldiers killed in Mali since 2013, AFP News agency quotes army staff as saying.
France's Minister for the Armed Forces Florence Parly tweeted that France had lost "two of its children" Sgt Yvonne Huynh and Brig Loïc Risser.
Sgt Huynh, aged 33 and mother of a young child, was the first female French soldier killed in Sahel, AFP adds.
Earlier in the week three other French soldiers were killed in Mali, also when an improvised explosive devise hit their vehicle.
In that instance militants from the Group to Support Islam and Muslims (GSIM), which is linked to al-Qaeda, said they were behind the attack.
No-one has yet said they carried out Saturday's attack.