Several people are missing after a collision between two cargo ships in the North Sea, one of which is believed to have sunk, German authorities said on Tuesday.
The accident happened early on Tuesday morning about 22 kilometres (13 miles) southwest of the island of Helgoland, the German Central Command for Maritime Emergencies (CCME) said.
Several ships are currently searching for survivors in the area, it added.
"One person was rescued from the water and is receiving medical care. Several other people are currently missing," the agency said.
The ship believed to have sunk was named as the Verity, sailing under a British flag and on its way from Bremen to the UK town of Immingham.
The other ship was the Polesie, under a Bahamas flag and travelling from Hamburg to La Coruna in Spain.
The Verity was the smaller vessel with a length of 91 metres (almost 300 feet), compared to the Polesie's 190 metres.
The Polesie was still afloat with 22 people on board, the agency said.
The Bild daily reported that a total of six people were missing.
"The emergency services are doing everything they can to rescue the missing people," German Transport Minister Volker Wissing said in a statement.
"My thoughts are with the crew members, their relatives and the rescue teams who have been in action since early this morning."
Cruise ship
Two rescue cruisers, an emergency tug, a pilot boat, a police patrol boat and a helicopter are helping with the search, according to the CCME.
A P&O cruise ship that was in the area, the IONA, has also been involved, the agency added.
"On board the IONA, people can also receive medical care; there are doctors on board," it said.
Other medical staff were also transported to the site by helicopter.
The search was taking place in difficult weather conditions, with winds of six on the Beaufort scale and waves reaching as high as three metres, the agency said.
The Polesie is owned by the Polish shipping company Polsteam.
The accident comes weeks after a ship with hundreds of electric cars on board caught fire in the North Sea off the coast of the Netherlands.
The Fremantle Highway was sailing between Bremerhaven in Germany and Port Said in Egypt when the blaze broke out in July.
The accident happened close to Ameland, one of an archipelago of ecologically sensitive islands situated in the Waddensee area.
All 23 crew members were evacuated from the ship, but one person died and several were injured.
Efforts to tow the ship to shore were complicated by poor weather conditions but it was eventually brought to the northern port of Eemshaven.
