As the report has specified, the operation was launched after a man had barricaded himself in an apartment.
The website Franceinfo, quoting a police source, reported that French special task forces are carrying out an operation in the town of Lourdes.
According to the Actu news portal, the man fired several shots.
It is suspected that the man had barricaded himself in a house with two or three other people inside.
The media says the police established a security perimeter around the house, with the residents of neighbouring houses being evacuated.