The Eiffel Tower in Paris was evacuated Wednesday when a suspicious package was found and an anonymous caller warned police that the monument was to be blown up at 5 p.m. local time.
An estimated 4,000 tourists were evacuated from the 1,063ft high tower after the package was found underneath the iron rafters, according to reports.
The site was still closed to tourists at 6:40 p.m. as police and bomb specialists investigated. But a police official later said a check of the site found no explosives, and tourists were allowed back on the sandy plaza beneath the tower after a little more than two hours.
Police have evacuated the Eiffel Tower several times in recent months because of bomb threats, according to the BBC. Each scare turned out to be a false alarm.
French President Nicolas Sarkozy was quick to support rebels fighting Muammar Gaddafi in Libya, and French jets began the attacks on the country, increasing fears that France may be the target of attacks from extreme Islamic groups.
Police are mainly concerned about two types of threat, according to the Daily Mail, both from Islamist extremists: an assassination bid on an important figure or an attack on a crowded area like a tourist spot or the Metro subway system.
According to the Mail, intelligence suggested that Al Qaeda's North African branch, Al Qaeda in the Islamic Maghreb, had been planning an imminent attack in France.
The Algerian intelligence agency has passed on warnings about militants heading to French to carry out attacks, and officials say there is also evidence of Jihadi fighters returning from Afghanistan and Pakistan.
Paris is the most popular tourist destination in the world.