One sailor has died and four others are missing after a British cargo ship sank after colliding with a vessel in the North Sea.
Germany's Central Emergency Management said two sailors were rescued, but the body of a man was recovered after the incident.
A search and rescue operation was launched after the British-flagged Verity hit a larger cargo ship, the Polesie, about 14 miles (22.5 kilometers) southwest of the German island of Heligoland at around 5am on Tuesday.
The conditions at the site are extremely difficult
Michael Ippich, German Naval Search and Rescue Service
While the larger Bahamas-flagged Polesie remained afloat, the Verity, which had departed from Bremen, Germany and was bound for the port of Immingham on the east coast of England, carrying steel coils, sank.
A short time later, the ship lost signal, German authorities said, and wreckage was found.
The search continues involving several ships, aircraft and a P&O cruise ship, with rescuers preparing to dive 30 meters to the wreckage.
Robbie Renner, the head of Germany's Central Command for Maritime Emergencies, told a news conference in Cuxhaven that it was possible the rest of the crew were still alive inside the sunken vessel and that his team was doing “everything humanly possible”. to save them.
Michael Ippich, of the German Maritime Search and Rescue Service, said the water temperature at the time of the collision was 12C (54F), which people can survive for about 20 hours.
Mr Ippich told reporters: “The conditions at the scene are extremely difficult.
“Because of the weather and the visibility, it's incredibly difficult to conduct such an operation.”
A P&O Cruises spokesman told the PA news agency: “P&O Cruises' Iona is currently involved in a search and rescue operation off the coast of Germany.
“The incident is ongoing and Iona's cooperation is in accordance with international maritime law as well as consistent with the company's ethical and legal obligations.
“Iona is scheduled to be at sea today and this event will have no effect on tomorrow's scheduled call to Rotterdam or the next itinerary.”
Faversham Ships Ltd, which owns the Verity, described the incident as “ongoing” and said it was working with local authorities.
A spokesman for Associated British Ports, which owns the port of Immingham, confirmed the ship was due to arrive there.
The Foreign Office has been approached for comment.