Seventeen people, including a child left in a critical condition, were injured when soldiers fired live bullets instead of blanks during an open day display in Carcassone, France, regional officials said.

Fifteen civilians and two soldiers were injured in the incident, of which the details remained unclear, involving a demonstration by members of a marines parachute regiment of hostage liberation exercises, the regional authority said.

Four of the 17 were seriously injured, with two described as critical following "incomprehensible" scenes at the barracks near Carcassone, in the country's south-west.