A policeman providing security for Francois Hollande accidentally fired his gun as the French president was giving a speech on Tuesday, injuring two people in the VIP area of the crowd, an official said.
Hollande was inaugurating part of a high-speed rail line in the southwest of the country when the mishap occurred.
"It was an accidental shot by a police officer which injured two waiters, or at least one waiter and an (event) employee. The injuries aren't life threatening," local government chief Pierre N'Gahane said.
"The bullet grazed one person's calf and then lodged in another person's leg," he said, adding that the victims were in a VIP area next to where Hollande was speaking.
The officer, who was helping to provide security for the president, was standing on an elevated point, N'Gahane said.
He made a "mistake in handling while changing positions", an informed source told AFP.
Video from the incident shows Hollande halting his speech after a bullet shot is heard in the background, with the president saying, "I hope there's nothing serious" and holding his hands up to the crowd.
But a few seconds later he says "I don't think so" and resumes talking about the railway project.
The victims were treated at the scene in a separate area from where the French president was speaking, before being taken away by firemen, who confirmed the injuries were minor.
N'Gahane told reporters that neither victim was in danger and that an investigation had been opened.
Hollande spoke briefly to the two injured guests before departing, N'Gahane said.
This is not the first mishap to occur during one of Hollande's speeches.
While he was running for the presidency a woman threw flour over him as he wrapped up a speech on housing problems, in protest over housing laws not being applied.
A shoe was thrown at him at another event on the campaign trail.
He said such events were "occupational hazards" but his security detail was boosted from two to 14 bodyguards after the flour attack.