A Dutch passenger ferry capsized after it was rammed by a German cargo ship early Friday on the Amsterdam-Rhine canal, police said, DPA reported.
Some of the passengers and the captain of the ferry were thrown overbroad. An initial search by police and divers with thermal imaging cameras has not found anyone.
Witnesses said the small pontoon ferry was turned over by the collision with the cargo ship, between Breukelen and Nieuwer Ter Aar on the 72-kilometre long canal.
The canal has been temporarily closed off whilst the rescue operation continues.
The captain of the German ship is being questioned by Dutch river police.
The canal links the port of Amsterdam with the Waal, the largest arm of the Rhine river.