On the morning of April 18, 1988, the oil platforms were knocked out. The U.S. forces then turned to look for Iranian frigates in the Strait of Hormuz, which joins the Gulf of Oman and the Persian Gulf. Sabalan's sister frigate was identified by aircraft from the aircraft carrier and drawn into a fatal engagement. Another group of A-6 Intruders was sent to the reported location of Sabalan in the strait, where the Sabalan fired at the A-6s at 6.17 p.m. (Gulf time).