Police in France also arrested the owner of a revolver found during Wednesday's raid, France's Interior Minister Bernard Cazeneuve said.
Security officials found jihadist documents at the mosque where yesterday's raids took place.
They have placed nine people under house arrest. Another 22 have been banned from leaving the country Mr Cazeneuve said.
France has been under a state of emergency since 130 people were killed in a series of terror attacks in Paris on November 13. Since then, some 2,235 homes and buildings have been raided, 232 people taken into custody, and 334 weapons confiscated.
Cazeneuve said the number of weapons apprehended so far is staggering.
He said: "In 15 days we have seized one-third of the quantity of war-grade weapons that are normally seized in a year."
This latest raid comes as authorities in a number of European countries crackdown on mosques suspected of being a breeding ground for extremists cells operating in the continent.
This week German authorities expressed concern refugees might be susceptible to radicalisation by Muslim extremists, who are using religion as an excuse to get closer to the new arrivals from Syria and other parts of the Middle East.
Officials said they have encountered at least 100 cases in which extremists have tried to establish contact with refugees. Those fleeing war and hunger in Syria and other parts of the Middle East, are allegedly being lured by rides, food, and shelter, as well as help with translation and traditional Muslim clothing.
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EU security officials suspect some mosques are being used as a breeding for terrorist cells
In the wake of last month's attacks in Paris, many European leaders have called for the suspension of the continent's refugee program.
Some EU leaders have also started to question the Schengen Agreement, which allows the EU's 400million residents and many non-EU nationals to travel freely across the continent, without the need to show any ID or wait in long queues whenever they cross a border.
