記事の中で気になった単語は"arrondissement"です。Oxford Dictionaries.comには"A subdivision of a French department, for local government administration"と定義されております。フランス語都市の「区」に相当する言葉のようです。（Ume）
Paris arrests: Four held amid France attack plot fears
French media reported that three men and a woman were detained at dawn in the 18th arrondissement of Paris and the nearby northern department of Seine-Saint-Denis.
They said at least one of those arrested had a prior conviction and had been under house arrest since last month, under new rules imposed after the November attacks.
Mr Cazeneuve said: "We have information about one person that suggests that he could undertake violent actions in France.
"This man could have been in contact with people in Syria and members of Islamic State. This person was arrested this morning along with three persons linked with him, and checks are underway."
But he warned people "to remain extremely cautious regarding some information on a planned and imminent violent action. We arrest people every day."
The Paris prosecutor's office said computer equipment seized during the dawn arrests would be analysed.