French police have arrested at least 10 people in an operation to dismantle a network sending would-be fighters to Syria.

Police announced ten arrests on Monday, mostly in the southern region of Toulouse, but also around Paris and in the northern region of Normandy, Interior Minister Bernard Cazeneuve said.

"Dismantling organised jihadist networks is a top priority for police," Cazeneuve said in a statement.

Agnes Thibault-Lecuivre, spokeswoman for the prosecutor's office, said four of those detained were already jailed for unrelated minor crimes.

The prosecutor’s office said it did not know how many fighters the network had recruited.

European officials fear that radicalised fighters will return from the battlefields of Syria and Iraq and attack at home, and France has made it a crime to recruit or be recruited for fighting abroad.

Authorities estimate around 1,000 French nationals have taken part in the conflict. According to figures published in the French Le Monde newspaper in November, about a quarter of those who left to join armed groups were converts to Islam.

France is currently using nine Rafale jets based in the United Arab Emirates as part of a US-led coalition to provide air support to Iraqi and Kurdish forces fighting the ISIL.

Source: Al Jazeera and agencies