(CNN) The suspect in Friday's knife attack at Amsterdam's central railway station had a "terrorist motive" and is believed to have acted alone, police in the Netherlands said Saturday.

Police said the suspect is a 19-year-old Afghan man who lives in Germany. Police would only identify him as Jawed S.

Two US citizens were stabbed, US and Dutch authorities said Saturday. The victims were seriously injured but are not in critical condition, the Amsterdam mayor's office said.

Police shot the suspect after the stabbings. A police spokesman told CNN the teenage suspect remains in a hospital, where he will be questioned later Saturday with the help of a translator.

Police in Amsterdam said they are in "intensive contact" with their German counterparts on the case. German authorities did a search of the suspect's house, where they found and seized data storage items that will be analyzed, police said.

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