BERLIN — A car drove at high speed into a pedestrian zone in the southwestern German city of Trier on Tuesday, killing at least two people and seriously injuring 15 others before being stopped by police, officials said.

The driver, identified as a 51-year-old German man from the area, was arrested at the scene and the vehicle was impounded, Trier police spokesman Karl-Peter Jochem said, according to news agency dpa.

Footage from the scene showed people outside a shop apparently helping someone on the ground lying among scattered debris.

"It was simply terrible," Mayor Wolfram Leibe told n-tv television after visiting the site. 

Leibe said the perpetrator "drove through the pedestrian zone, clearly at high speed, and killed several people and injured several, some of them seriously."

The driver is being questioned by police, he said.

"I don't want to speculate, but all of us are asking ourselves … what drives a person to do something like this?" Leibe said. "Of course I don't have an answer to this question."

The area was being kept shut down until at least Wednesday morning for police to collect evidence, but there was no longer any danger, Leibe said. 

In a video posted by a local media outlet purportedly showing the arrest, police could be seen pinning a man down on the sidewalk next to a car with Trier license plates. The authenticity of the video could not immediately be verified and it was taken down shortly after police tweeted a request that people do not share photos and videos of the scene.

Trier is about 200 kilometers (120 miles) west of Frankfurt, near the border with Luxembourg. The city of about 110,000 people is known for its Roman gate, the Porta Nigra, which is near the scene of the crash, and as the birthplace of Karl Marx.