The two people injured in a stabbing incident on Friday at Amsterdam's central station were US citizens, the US ambassador to the Netherlands said in a statement on Saturday.
Ambassador Pete Hoekstra said the pair were tourists visiting the city. They remained in hospital on Saturday, with serious injuries, local police said.
Police said the attacker, a 19-year old Afghan citizen who was shot and taken into custody shortly after the incident, would be interrogated later in the day. He also remained in hospital, with injuries to his lower body.
On Friday evening, police said the man's motives were still unclear. "All scenarios are taken into consideration, including a terrorist motive", authorities said in a statement.