France's ministry of defense is to carry out checks on security at all its military bases after thieves managed to break into a base in southern France and make off with explosives and scores of detonators.
The arms were stolen from munitions depot on the base at Miramas in Provence, Europe 1 radio claimed on Tuesday.
The break in, which is said to have occurred on Sunday evening, saw thieves cut their way through the wire fences into the compound.
They pilfered up to 190 detonators and a stock of plastic explosives as well as around 40 grenades.
Investigators are still trying to determine exactly what is missing and it may yet turn out that other military weapons and devices were stolen.
After initially declining to comment the ministry of defense said later on Tuesday that an evaluation will be carried out around all army bases to determine whether there was adequate security.
Details of the theft have been reported to the French government and the president, who will no doubt be highly concerned given France's heightened terror alert since January's attacks in Paris.
While the investigation is reportedly focusing on organised crime, they have not ruled out that the arms may have been stolen by would-be terrorists.
The 200 acre base is used as a logistics centre as well as for stockpiling munitions used in France's foreign operations.
There are reportedly no surveillance cameras around the compound's fences.
The local mayor of Miramus, Frederic Vigouroux, was extremely concerned.
"This is a site that is highly secure and well guarded. All state services are on tenterhooks," he said.
France has been on high alert since a jihadist killing spree six months ago in Paris that left 17 people dead, including 12 people gunned down in the editorial offices of satirical magazine Charlie Hebdo.
The country is high on the hit list of Islamic State jihadists.
In the most recent attack in France, a 35-year-old found to have links to an Islamic State fighter in Syria beheaded his boss at a gas factory in Lyon and rammed a van full of gas bottles into a warehouse, creating an explosion.
It was as yet unclear what was behind the theft in Miramas, but this is not the first time that a large quantity of explosives has been stolen in France.
In July 2008, thieves took 28 kilos of explosives from a bomb disposal unit just outside Lyon.
Then interior minister Michele Alliot-Marie had blamed "faults in the site's security."