Footage from the scene show a stampede of people running away from the direction of the tower itself during the Italy vs Germany match.
Social media users at the fanzone, which can hold up to 90,000 people, shared a general sense of panic, with the tweeter below reporting that some were suggesting there was a fire.
One tweeter wrote that she was “terrified
” and “genuinely believed” she was “under threat”.
More footage (below) showed scores of people pouring out of the fanzone and into the streets.
Several people suffered minor injuries from the stampede, reported Le Parisien newspaper.
Despite the panic there was no official evacuation of the fanzone, and many people, while jittery, still hung around to watch Germany knock Italy out of the tournament.
It remains unknown how fans managed to smuggle firecrackers into the venue, which has at least two set of security screenings before fans can even enter.
There have been reports, however, that at least one fan has smuggled a flare into a French stadium during this tournament by inserting it into his rectum
. It's unknown if a similar approach was employed on Saturday night.
France and especially Paris have been on high alert ever since terrorists killed 130 people in a series of coordinated attacks in November last year.