Paris police say they spotted at least five drones flying over the French capital overnight, and an investigation is underway into who was flying them and why.

France's BFM television reported that they were seen flying over the Eiffel Tower, the Louvre Museum and the American Embassy, among other locations.

A Paris police official confirmed the presence of the drones in Paris airspace, but would not provide other details. The national gendarme service said an investigation is underway.

In recent months, France has seen dozens of mystery drones flying over nuclear plants and military installations. One flew over the presidential palace.

French authorities have said the drones currently present no threat, but the government has asked scientists to help devise ways to counteract the devices.