BONN (Reuters) - A German Tornado jet with two officers on board has been missing since Tuesday evening when it disappeared over the North Sea, the German navy said on Wednesday. The navy said the plane lost radar and radio contact about 10 sea miles off the island of Borkum on the way back from a training flight over the Netherlands. German and Dutch aircraft and boats were taking part in a search operation which had not yet yielded any results, the navy said in a statement. There were no indications as to what had caused the accident, it added.