Drones have appeared over landmarks in central Paris for the second night running and police are no nearer knowing who is operating them, the BBC reports.
There were five sightings by police and the public between 23:00 on Tuesday and 02:00 (01:00 GMT) on Wednesday, French media report.
Up to three drones were seen near the Invalides military museum, Place de la Concorde and two of the old city gates.
Flying over Paris at night is illegal and low flights need authorisation.
Five drones were seen the previous night in similar areas, including the Eiffel Tower and above the US embassy, close to Place de la Concorde.
However, some of the latest drone flights have been captured on film and will be analysed by a 10-strong team of investigators set up after the first incidents.
The new sightings were also on the fringes of central Paris, at the key transport gates of Porte de Clignancourt in the north and Porte de Saint-Cloud in the south-west.
Small drones are inexpensive and easy to buy but their appearance in recent months over sensitive locations has worried French authorities.