The target on the ground was designated by US and British troops engaged with Taliban fighters, the ministry said, adding that it had been hit. The incident took place on October 30.
In the past four months, French aircraft have opened fire eight times in Afghanistan, it said.
The Mirage's action was part of the Serpentaire air support mission. Three fighters are based at Dushanbe in Tajikistan and a C-135 refuelling aircraft at Manas in Kirghizstan.
They are part of France's contribution to Operation "Enduring Freedom" and support for the NATO-led International Security Assistance Force (ISAF) in Afghanistan.

Copyright AFP (Agence France-Presse), 2006