It was not immediately clear how many casualties there were. Witnesses said victims were crushed by the truck.
The incident Monday evening happened at Breitscheidplatz, a public square in the center of the German capital. Police were still investigating the chaotic scene, the spokesperson told NBC News.
It wasn’t clear whether the truck veered into the holiday crowds on purpose or by accident. Local German media cited police saying indications pointed to an attack, not a traffic accident.
Last July, a truck driver killed 84 Bastille Day revelers in Nice, France, and injured more than 200, before he was shot dead by police. Officials said he had been planning the attack for months.
U.S. officials have long feared truck attacks on American soil. Permanent truck barriers were installed around government buildings nationwide after the 1995 truck bomb attack in Oklahoma City.