Three Al Jazeera journalists were arrested on Wednesday for allegedly flying a drone over key landmarks in the French capital, legal sources said.The prosecutor's office said that the three foreign nationals, aged 34, 52, 68, were detained on Wednesday afternoon after being spotted by the police as they were flying a drone in the Bois de Boulogne woods in western Paris.The incident is as of now not related to the drone sightings in the capital on Monday and Tuesday, it said.A staff member at Al Jazeera's Paris office told The Anadolu Agency that they learned of the incident from the TV, and were yet to get hold of their co-workers. An investigation has been launched after several unmanned flying objects were sighted over key landmarks on Monday and Tuesday nights including Eiffel Tower and the U.S. Embassy. According to French law, it is illegal to fly drones without a license, and violators could be sentenced to prison for up to one year, and fined up to EUR 75,000 ($85,000).