 Other PAVN forces continued to move south towards Đông Hà on the afternoon of 2 April, engaged first by limited tactical air strikes and then by artillery, mortar and tank fire.A large search and rescue effort had been launched for the crew of a US aircraft downed near Cam Lo.The U.S. Air Force temporary no-fire zone was 27 km in diameter, encompassing nearly the entire combat area and South Vietnamese defenders were unable for several hours to call for artillery support or tactical air strikes against the onrushing PAVN.