The Eiffel Tower was briefly evacuated Tuesday evening after officials received a bomb threat called in from a telephone booth, in the second such alert at the monument in two weeks.
The warning came as French officials have been on alert for possible terror attacks on crowded targets.
Police closed off the immediate surroundings of the tower, France's most visited monument, blocking off traffic. Officers pulled red-and-white police tape across a bridge leading over the Seine River to the monument. Dozens of officers stood guard in the area.
Bomb experts combed through the 324-meter (1,063-foot) tower and found nothing unusual, the Paris police headquarters said. Tourists were let back inside about two hours after the structure was emptied.
Jean Dupeu, a 74-year-old Paris retiree, had planned to go to dinner in the tower but found himself looking for another restaurant.
"It's surely a bad joke," he said of the threat, adding, "Now is not a good time."
National Police Chief Frederic Pechenard said last week that authorities suspect al-Qaida's North African branch of plotting a bomb attack on a crowded location in France. His warning came after Al-Qaida in the Islamic Maghreb, or AQIM, claimed responsibility for the Sept. 16 abduction of five French nationals and two Africans in northern Niger.
The French parliament voted this month to ban burqa-style Islamic veils in France, a subject that has prompted warnings by AQIM. Counterterrorism officials say that is just one of several factors contributing to the heightened threat.
At the Eiffel Tower, an anonymous caller using a phone booth in a nearby neighborhood called in a warning to firefighters, the Paris police headquarters said. The company that runs the monument asked police to evacuate it.
Police responded to a similar false alert at the tower on Sept. 14, also following a phone threat. On Monday, the bustling Saint Lazare train station in Paris was briefly evacuated and searched.
As soon as the latest bomb alert ended, huge lines of eager tourists immediately formed under the tower.
Mike Yore, 43, of Orlando, Florida, was among those waiting in line who had no idea the 121-year-old iron monument had even been evacuated.
"There's no bomb that can blow this thing up," he said.