The Mystere IV was an evolutionary development of the Mystere II aircraft. Although bearing an external resemblance to the earlier aircraft, Mystere IV was in fact a new design with aerodynamic improvements for supersonic flight. First prototype flew on September 28, 1952, and the aircraft entered service in April of 1953. The first 50 production aircraft were powered by British Rolls-Royce Tay turbojets, while the remainder had the French-built Hispano-Suiza Verdon 350 version of that engine.Israeli Mystere IVs saw action during the Arab-Israeli Wars and were joined by the French Mysteres for the Suez crisis. On June 8, 1967, Israeli aircraft were involved in the tragic and controversial attack on USS Liberty. Indian aircraft were used in the Indo-Pakistani War of 1965.