France’s interior ministry, responsible for expelling foreigners, was not available to confirm the information, which had been initially reported by Europe 1.

France defines extremists as “people who, engaged in a process of radicalisation, are likely to want to go abroad to join terrorist groups or take part in terrorist activities”.

Of the total number of suspects, 180 people are currently in prison and 51 were due to be arrested in the next hours, the police union source said.