The Eiffel Tower was completely evacuated on Friday afternoon following a bomb alert, a police official said.
The 324-metre-high (1,062-foot) iron tower was evacuated around 2 pm (12:30 GMT) and had not reopened to tourists by 4 pm. The police official could give no further details.
Built in 1889 and one of the world's most recognisable monuments, the Eiffel Tower sees some 7 million visitors each year and up to 30,000 a day in the peak summer season.
It is regularly subject to bomb scares but these threats are usually quickly found to be hoaxes and only cause full evacuations a couple of times a year.