Dozens of cruise ship passengers who fell ill during their voyage were temporarily held on board Thursday after the liner moored in the Dutch port city of Rotterdam.

The sickened passengers were on board the AIDAperla. The ship's German operator Aida Cruises said in a statement that crew increased hygiene measures after "gastro intestinal infections occurred among passengers."

Local emergency services said in a statement that 70 passengers reported feeling sick and received treatment onboard.

By early afternoon, port authorities and the cruise company said that all passengers were being allowed on and off the ship.

It was not immediately clear how many passengers the ship was carrying.