On the night of 2 August 1964 the Gulf of Tonkin incident occurred in which North Vietnamese gunboats directly clashed with United States Navy destroyers. At Clark, the base went on alert and the atmosphere was that of a wartime appearance. Fighter Squadrons were deploying to USAF bases in Thailand, and transports began shipping supplies and equipment to South Vietnamese bases used by the United States. The two B-57 squadrons went on alert and on 5 August the squadrons were notified to deploy 20 B-57Bs of the 8th and 13th BS to Bien Hoa Air Base near Saigon. This would mark the first deployment of jet combat aircraft to Vietnam.