AMSTERDAM — A knife-wielding assailant in Amsterdam seriously wounded five people, including two from the United States, one from Belgium and one from Poland, in a stabbing attack Thursday on a busy shopping street, Dutch police said.

The attack lasted several minutes before the assailant was stopped and injured by a passerby near the city’s Dam Square in the late afternoon. Police cordoned off the area and several ambulances and a trauma helicopter were called to the scene.

Authorities said in a statement that no motive had been established for the attack, but that police were considering a scenario where the man targeted victims at random.

The victims were identified as a 67-year-old woman and a 69-year-old man from the United States, a 73-year-old woman from Belgium, a 26-year-old man from Poland and a 19-year old Dutch woman from Amsterdam.

Amsterdam Mayor Femke Halsema said in a statement, “Our hearts go out to the victims, their families and loved ones.”

— The Associated Press