Six Israeli and one Romanian servicemen are missing after losing radio contact over Romanian mountains during joint training exercise in poor weather on Monday.According to Israeli defence ministry, the seven airmen were conducting a joint military exercise when their Israeli helicopter went down in an inaccessible area in the Carpathians some 150 kilometers north of the capital Bucharest. In the past, Israel has conducted military exercises with a number of Eastern European countries. The Israeli Air Force cancelled training flights for Tuesday, in the wake of Monday's crash.