BERLIN — A driver intentionally plowed a truck into a crowded Christmas market in central Berlin Monday night, killing at least 12 people and injuring 48 others in an act police called a "suspected terror attack."
The truck rammed though market stalls next to the Kaiser Wilhelm Memorial Church, striking scores of people as it sped through a passage of the popular market. A Polish man riding in the truck died at the scene, authorities said.
"Our investigators are working on the assumption that the truck was intentionally driven into the crowd at the Christmas market on Breitscheidplatz, Berlin police said on Twitter. "All police measures concerning the suspected terror attack at Breitscheidplatz are being taken with great speed and the necessary care."
Police arrested a suspect about two kilometers from the crash scene but said that "whether it's the driver of the truck is currently under investigation." Authorities did not release the driver's nationality and later said they suspected the truck, which had Polish license plates, had been stolen.
Berlin police spokesman Winfried Wenzel told Germany's WeltN24 that a witness followed the suspected driver, who fled on foot, from a distance. The witness then called police, relaying the location of the suspect over the phone.
The witness followed the driver the entire distance until the person was picked up in a patrol car, Wenzel told WeltN24.
"He probably wanted to find shelter in the darkness" of Berlin's central park Tiergarten, he said.
"It wasn't an accident," witness Emma Rushton told Sky News. "When [the truck] was going 40 miles an hour, it was the middle of the market."
The US condemned the crash, saying the deadly incident appeared to be a terror attack.
"The United States condemns in the strongest terms what appears to be a terrorist attack," National Security Council spokesman Ned Price said in a statement. "We have been in touch with German officials, and we stand ready to provide assistance as they recover from and investigate this horrific incident. Germany is one of our closest partners and strongest allies, and we stand together with Berlin in the fight against all those who target our way of life and threatens our societies."
President-elect Donald Trump called it a "horrifying terror attack," and referred to recent attacks carried out by ISIS and Islamic terrorists.
"Innocent civilians were murdered in the streets as they prepared to celebrate the Christmas holiday," Trump said in a statement. "These terrorists and their regional and worldwide networks must be eradicated from the face of the earth, a mission we will carry out with all freedom-loving partners."
However, there was no statement or confirmation from officials in Germany that the crash was a terrorist attack.
Authorities repeatedly insisted in local media it was too early to know whether the deadly incident was a terror attack and investigators are still looking into what the motive of the crash may have been.
"It's a terrible evening for Berlin and our country, one that shocks me like so many other people," said German President Joachim Gauck.
Rushton told Sky News there were two roads on the side of the square, but the truck drove through the middle of the market.
"There is no way that it could have come off the road and it showed no signs of slowing down," she said.
German broadcaster ARD reported that the owner of the transportation firm that owns the truck said on Polish television that his cousin was driving the truck from Italy to Poland, with a stop in Berlin. But the owner insisted his cousin "could never commit an attack" and suspected something happened to him, perhaps kidnapping.
The truck, police said, was carrying steel beams for construction.
On social media, police also announced that the rest of the city was safe, but continued to urge people to stay indoors.
German Chancellor Angela Merkel was reported to be in touch with Berlin's mayor over the incident.
Heiko Maas, Germany's federal minister of justice, offered his condolences to the families of the victims and said the attorney general would be taking over the case.
The attack occurred at the popular Christmas market next to the Kaiser Wilhelm Memorial Church, which was bombed in 1943 during World War II and left in ruins as a reminder and warning of war.
It is an area that is often busy with foot-traffic and shoppers.
Police urged people to avoid the area and refrain from posting rumors or false information on social media. Officials also asked people not to share gruesome images from the scene, to protect victims' rights to privacy.
Pictures and videos on social media showed ambulances and police arriving at the square where a truck can be seen tilting next to shops.
The crash evoked memories of the Bastille Day attack in Nice, where more than 80 people were killed when a truck drove through a crowd that had gathered to celebrate the national holiday.
The French-Tunisian driver of that truck was shot and killed by police.
Following Monday's incident, French President François Hollande offered his solidarity to the German people.
Sal Hernandez and Talal Ansari reported from New York City. Jina Moore reported from Berlin, where Saba MBoundza and Dani Beck also contributed reporting.