At least 12 people were killed on Monday evening when a truck plowed into crowds at a Christmas market in the German capital of Berlin.

48 people were injured, some of them seriously. Police previously said that 9 people had died and at least 50 were injured.

The attack happened at about 8:00 p.m. local time on Breitscheidplatz, which is located in western Berlin. Multiple stalls at the market were damaged by the truck.

A suspect, likely the driver of the truck, has been arrested, the BBC reported. The suspected co-driver was found dead, police said.

The truck was registered in Poland, according to reports, and its owner claimed it had been hijacked.

Police told the German news agency dpa that they are treating the incident as a suspected attack, though Berlin State Interior Minister Andreas Geisel did not rule out that the incident could have been an accident.

Witnesses, however, said the crash was not an accident and added the truck had shown no signs of slowing down, according to Sky News.

They spoke of the vehicle "going through people" and "pulling everything down" as it tore through tables and wooden stands.

The Israeli embassy in Germany is in contact with police in order to obtain information about whether any Israelis were present at the site.

The attack in Berlin is very similar to the attack in Nice, France, this past July, in which a truck plowed into a crowd celebrating Bastille Day.

86 people were murdered in the Nice attack, which was claimed by the Islamic State (ISIS) group.

Germany has been under a high-threat terrorist alert following a series of attacks which hit the country this past summer.

In the first attack, a 17-year-old Afghani with an ax attacked passengers on a train in Wurzburg before being shot dead by security forces.

In the second incident, an attacker set off a bomb in a restaurant in Ansbach, killing himself and wounding 12 others.

A German court recently jailed three young men for up to four and half years for travelling to Syria where they teamed up with jihadists.