B-57 Canberra. The U.S. replied on 19 July that no American "military planes" had overflown the Soviet Union, but the fact that the Soviets' report showed that they could track the U-2s for extended periods caused Eisenhower to immediately halt overflights over eastern Europe. Beyond the Soviet protests, the president was concerned about the American public's reaction to the news that the U.S. had violated international law. To avoid project cancellation, the CIA began Project Rainbow to make the U-2 less detectable. The eight overflights over communist territory, however, had already shown that the bomber gap did not exist; the U-2s had not found any Myasishchev M-4 Bison bombers at the nine bases they had visited. Because the Eisenhower administration could not disclose the source of its intelligence, however, Congressional and public debate over the bomber gap continued. Suez Crisis and aftermath The presidential order did not restrict U-2 flights outside eastern Europe. In May 1956, Turkey approved the deployment of Detachment B at Incirlik Air Base, near Adana, Turkey. Before the new detachment was ready, however, Detachment A in late August used Adana as a refueling base to photograph the Mediterranean. The aircraft found evidence of many British troops on Malta and Cyprus as the United Kingdom prepared for its forthcoming intervention in Suez. The U.S. released some of the photographs to the British government. As the crisis grew in seriousness, the project converted from a source of strategic reconnaissance, which prioritized high quality over speed (the film was processed by its maker, then analyzed in Washington), to a tactical reconnaissance unit that provided immediate analysis. The Photo Intelligence Division set up a lab at Wiesbaden; as Detachment B took over from A and flew over targets that remain classified , the Wiesbaden lab's rapid reports helped the U.S. government to predict the Israeli-British-French attack on Egypt three days before it began on 29 October. On 1 November a flight flew over the Egyptian air base at Almaza twice, 10 minutes apart; in between the British and French attacked the base, and the visible results of the attack in the "10-minute reconnaissance" impressed Eisenhower. Beginning on 5 November, flights over Syria showed that the Soviets had not sent aircraft there despite their threats against the British, French and Israelis, a cause of worry for the U.S. In the four years following the Suez Crisis, repeated U-2 missions over the