Anti-terror police say they found a Kalashnikov assault rifle, a pump action shotgun and munitions when they brought in nine people in the cities of Marseille and Avignon Tuesday morning.
The raids were on the orders of a Parisian anti-terrorist judge leading an inquiry into alleged terror plots.
But sources told the AFP wire agency that it was pure coincidence that they came on the same day as three other arrests, one in Marseille and two near Bordeaux, of men whose contact details were found on Ryad Hannnouni, arrested in Naples in possession of bomb-making material on Saturday.
Hannouni had just returned from the tribal zones on the Pakistan-Afghanistan border, where he is believed to have fought with the Taliban or their allies.
France has demanded his extradition so that he can be questioned on the so-called “Afghan networks” of former fighters who have returned to western Europe. But the sources say the three men arrested Tuesday may only be wanted for relatively minor crimes, such as faking official documents.
The raids come after the US, followed by the UK, Japan and Sweden, issued a terror alert for western Europe and advised European capitals that Al-Qaeda was planning co-ordinated strikes in various countries.
In a separate assessment, French intelligence warned of attacks allegedly being planned in Europe by Al-Qaeda in the Islamic Maghreb (Aqim), which is now believed in EU capitals to be a graver threat than Osama bin Laden.