The Louvre Museum in Paris and Versailles Palace evacuated visitors and staff on Saturday after receiving bomb threats, police said.
The move came as the French government started deploying 7,000 troops to increase security around the country after a fatal school stabbing by a suspected Islamic extremist.
The evacuations of two of the world’s most-visited tourist sites come amid heightened vigilance around France following Friday’s school attack, and global tensions linked to the war between Israel and Hamas.
President Emmanuel Macron’s government is worried about fallout from the war in France.
Alarms rang out through the Louvre when the evacuation was announced, and in the underground shopping centre beneath its signature pyramid.
Paris police said officers searched the museum after it received written bomb threats.
The Louvre communication service said no-one was hurt and no bomb was found, so the museum will reopen as usual on Sunday.
The Louvre, home to masterpieces such as the Mona Lisa, welcomes between 30,000 and 40,000 visitors per day and several million annually.
The former royal palace at Versailles also received bomb threats, and the palace and its sprawling gardens were being evacuated while police examine the area, according to national police.
A major Paris train station, Gare de Lyon, was also evacuated after the discovery of a possible bottle explosive, police said.
