The Dutch authorities said on Saturday that the suspect in a double stabbing at a busy railway station in Amsterdam had “a terrorist motive,” while the United States ambassador to the Netherlands identified the two people injured as American citizens.

In a statement, Ambassador Pete Hoekstra said that the Americans had been visiting the country when the attack happened on Friday and that the embassy had been in touch with their families. He did not identify the two people.

“We wish them a speedy recovery and are working closely with the City of Amsterdam to provide assistance to them and their families,” the statement said.

The police in Amsterdam said that officers had shot and detained a 19-year-old Afghan man in the stabbing. He was identified on Saturday only as Jawad S., in line with Dutch privacy laws, The Associated Press reported. His initial statements to the police pointed to an extremist motive, officials said in a statement, according to local media reports.