Paris prosecutors say a counterterrorism judge is questioning a 16-year-old French girl who allegedly supports the Islamic State group and is suspected of trying to perpetrate an attack.

The Paris prosecutor’s office says the girl was using a social media app to spread calls by IS to commit violent acts.

Deputy prosecutor Laure Vermeersch said Monday that the judge may decide to file preliminary terrorism charges against the teenager who was arrested last week in a Paris suburb and has been held in custody since then.

The investigators said the girl was “extremely radicalized” and was the administrator of a chat group dedicated to IS propaganda on the Telegram app, which has been used by suspected jihadis to communicate.