The aircraft “was flying between Spain and Cologne, but when it changed course, air traffic controllers were unable to make contact,” Latvia’s civil aviation service said in a statement. German newspaper Bild reported that the plane reported shortly after takeoff that there was a problem with cabin pressure. Fighter jets from Germany, Denmark and Sweden tried to contact the crew in the air as the plane continued to fly over northern Europe, “but they didn’t see anyone,” the head of the Swedish search and rescue operation told AFP Lars Andonsson. The plane, an Austrian-registered Cessna 551, flew over Swedish airspace over the Baltic Sea before crashing into the sea off Ventspils shortly before 20:00 (18:00 GMT). The plane flew relatively steadily until it approached the coast of Latvia, when it rapidly lost altitude. It crashed “when it ran out of fuel,” Antonsson said. The nationalities of the four passengers were not immediately known. German media reported that the passengers were a family of three – a man, a woman and their daughter – in addition to the pilot. “Rescue teams with boats and helicopters from Latvia, Lithuania and Sweden are working at the crash site,” the Latvian aviation service said. “No human remains have been found,” Antonsson added. It is not known what caused the plane to go off course. Archie Bland and Nimo Omer take you to the top stories and what they mean, free every weekday morning Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. “We have absolutely no explanation, we can only speculate” about what happened, Antonsson said, “but they were clearly incompetent on board.” Agence France-Presse and The Associated Press contributed to this report.