Story highlights

Security officers in Paris spotted three people climbing the Eiffel Tower on Sunday

French police say officers and a helicopter were dispatched but the group escaped

The 312-meter metal tower is a landmark in the French capital visited by millions annually

Paris CNN  — 

Three people are on the run in France after being sighted climbing Paris’s landmark Eiffel Tower early Sunday, police say.

Security agents called police after seeing the group at 5:30 a.m., but the climbers escaped before officers arrived, a police department spokesman told CNN.

A police helicopter equipped with a thermal imaging camera was also dispatched.

An emergency response unit thoroughly inspected the tower, which eventually opened to the public late in the afternoon, the spokesman said.

The Eiffel Tower was evacuated twice in 2010 due to bomb threats and once in 2013 over security concerns.

The tower is a French icon, with almost 7 million people visiting it annually.

Built by Gustave Eiffel, it was completed in 1889 as part of a “Universal Exposition” celebrating the centenary of the French Revolution.

At 312 meters (1,024 feet), the metal tower was the tallest structure in the world until New York’s Chrysler Building overtook it in 1930.

It was originally designed as a temporary attraction, but the decision was made to keep it as a permanent attraction – and the Tower has never looked back.

Last year it unveiled a glass floor as part of a $38.4 million renovation.

Noisette Martel reported from Paris and Susannah Cullinane contributed from London.