On Saturday afternoon, a stationary tram at the underground stop at Strasbourg's main railway station was violently hit by another tram, which began to move backwards for unknown reasons.

The moving tram, which had stopped due to a traffic jam, reversed and rolled down a slope leading to the station.

Both trams carried dozens of passengers.

As a result of the collision, 68 people were injured, according to the prefecture, which released an updated toll Sunday.

Around a hundred people escaped unharmed.

The collision occurred near Strasbourg's main train station, one of the busiest in France outside of Paris.

Video footage posted online showed chaotic scenes with the two trams significantly damaged, an alarm going off and people screaming.

"The tram set off again at full speed towards the station," said Romaric Koumba, one of the passengers.

"As we were setting off again towards the station, we realised that there was already another tram that had returned to the station. This tram was at a standstill, thank God," said Romaric Koumba, one of the passengers.

"When the tram collided with the other one, the doors flew off," he added.

Another witness, Johan Kirschenbaum, said the moving train apparently had a problem with the brakes.

"We heard a big impact, a big bang," he said.