"There is no pretext that justifies such a unilateral action," the French foreign ministry said in a statement, adding that it "threatens thousands of civilians already affected by a month-long illegal blockade and which runs against efforts by the international community to reach a negotiated settlement."
Azerbaijan has launched a military operation in Karabakh almost three years after it went to war with Armenia over the disputed mountainous region.
Blasts were heard Tuesday in the Armenian separatist stronghold of Khankandi which Armenians call Stepanakert in the breakaway region.
They said Karabakh towns and cities were “under intensive fire”.
The developments come after months of mounting tensions between the Caucasus neighbors and hours after Baku said six Azerbaijanis were killed by mine explosions in Karabakh, blaming Armenian separatists.
The escalation occurred a day after badly needed food and medicine was delivered to Karabakh along two roads simultaneously, a step that looked like it could help ease mounting tension.
Armenia and Azerbaijan have been locked in a decades-long conflict over Karabakh, going to war in the 1990s and in 2020.
MNA/PR