AMSTERDAM - An Afghan man shot by police at Amsterdam's central station on Friday after stabbing two US tourists had a "terrorist" motive, city officials said on Saturday.

The suspect, who was identified as a 19-year-old Afghan with a German residence permit, was questioned on Saturday in hospital where he was being treated for gunshot wounds to his lower body.

"First statements made by the suspect indicate he had a terrorist motive," Amsterdam city council said in a statement.

German police searched the man's house at the request of their Dutch colleagues and seized several data carriers, the authorities said.

The suspect, who is being held in solitary confinement, will be brought before a judge on Monday to decide whether he should remain in custody.

The two people injured in the incident 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.

The local government said on Saturday it had no immediate plans to beef up security in the city, saying the swift action by police "shows that Amsterdam is prepared for this kind of incident".

A passerby's dramatic photo showed two police officers pointing guns at a man in bluejeans and sneakers lying on the ground inside a train station tunnel.

Earlier on Saturday, the US ambassador to the Netherlands confirmed that the two people injured on Friday were US citizens visiting the country when they were stabbed at the station.

Ambassador Pete Hoekstra issued a written statement saying US Embassy officials had been in touch with the victims or their families.

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

Central Station is a busy entry and exit point for visitors to Amsterdam, with regular trains linking it to the city's Schiphol Airport. Friday is one of the busiest days of the week for train travel as tourists arrive for the weekend. The station is patrolled by armed police and other security staff.

Earlier this week, Dutch police arrested a 26-year-old man suspected of threatening to attack far-right politician Geert Wilders over his plan to hold a contest of cartoons depicting Islam's Prophet Muhammad.

Wilders on Thursday canceled the contest citing security risks, as thousands of people in Pakistan marched in protest of his plan, while the Taliban in Afghanistan called for attacks on Dutch troops serving in the country.

The last major attack in the Netherlands was the killing by a Muslim radical of Theo van Gogh, the outspoken film maker and great-grandnephew of the famous painter, in 2004.

AP - Reuters