Tourists visiting the popular attraction are believed to have been trapped in the Paris landmark as armed police surrounded its base amid reports of a ‘gunman’ on the loose.
Images from the scene show a police cordon surrounding the attraction, with witnesses being approached by police.
Some even appear to be being searched as officers cleared the area.
One person tweeted: “#EiffelTower is shut off with a large security presence from Trocadéro – trying to see what if anything is going on…”
Another said: “#EiffelTower something not right?”
Witnesses posted on social media to say the whole area around the tower’s base has been cleared and staff and tourists have been kept lcoked inside while officers investigate.
French police have confirmed they arrested a man near the Eiffel Tower in Paris on Friday night.
A Paris police official said: “A person was arrested, the incident is finished.
“He wasn’t armed, we’ll know more about his motives tomorrow.”
The incident sparked had sparked panic in the iconic Paris monument.
Bob Thomas said on Twitter: “Anyone know what is going on at the Eiffel Tower? All been shut down.
“We’re stuck in one of the legs outside the lift. We’ve been locked in. They say another 30 minutes.
“Told it’s a full lock down. We have been locked inside.
“We are currently locked down at the base outside one of the lifts.
“Been told a guy was acting weird but no confirmed weapon. The staff have been locked in with us. Confirmed incident though.
“Everything is back on track. Man acting “weird” on second floor. Full lockdown. Man arrested.”
The Eiffel Tower has now reopened following the incident and trapped tourists have been allowed out.
The Eurostar terminal at Gare du Nord train station has also been evacuated amid a security alert, leaving hundreds of British passengers facing travel chaos.
Passengers at the scene say security officials found a suspicious package and evacuated everyone from the station at the north of the city.
The incident has now been resolved and passengers allowed back in the terminal.
But it has been confirmed that all passengers will now have to go through all check-in and border controls again – with services currently expected to be delayed by around two hours.
Eurostar tweeted: “We regret that for security reasons check-in and border conrols will need to be repeated for customers of #ES9063.
“There will be a consequent delay to the departure of #ES9063. Thank you for your understanding.”
With additional reporting by Nicole Stinson.