One of the men killed was named as Amada Ag Hama, who has been linked to the murder of two French journalists in 2013.
Release of Serge Lazarevic after being held by Islamists for three years means there are now no more French hostages anywhere in world.
Serge Lazarevic, held in the Sahara for almost three years since kidnapped in Mali, asks French president 'to do everything to free me'.
Targets revealed in online messages between a 29-year-old French citizen and a 'senior member' of al-Qaeda offshoot group.
Serge Lazarevic, who was captured two years ago by Al Qaeda's North African wing AQIM, called for help from President Hollande.
President Hollande says there is "all reason" to believe the French hostages being held by al Qaeda in the Islamic Maghreb (AQIM) are alive.
Abou Zeid, who was a senior figure in al-Qaeda in the Islamic Maghreb (AQIM), was killed during fighting in northern Mali at the end of February.