The woman was arrested on suspicion of planning an attack on a church in the French city of Montpellier, say anti-terrorism investigators.
A woman has been arrested on suspicion of planning an attack on a church in the French city of Montpellier, say anti-terrorism investigators.
During searches of the suspect's home - at a housing project in the southern town of Beziers - authorities found a printed photograph of French teacher Samuel Paty, alongside other images of "armed jihadists".
Bomb-making materials were found in the 18-year-old's apartment, as well as a diagram of a nearby church and handwritten notes referring to Nazism and the Islamic State group, officials said.
The suspect has not been identified by the authorities and was "unknown to the intelligence services".
Anti-terrorism authorities said they had launched an investigation into the individual for "criminal terrorist association" and "possession of incendiary or explosive products".
The mother and three sisters of the young woman were also initially arrested, but have since been released.
"No evidence was found to implicate [the] sisters and mother in the preparation of a plan for violent action," prosecutors said.
The 48-year-old teacher Paty was assassinated outside his school near Paris in October, after showing caricatures of the Prophet Mohammed to students during a class on freedom of expression.
The beheading shocked France and led to renewed fears over Islamist attacks in the country.