Soviet Union and Democratic Republic of Afghanistan Air Force jet fighters and bombers would occasionally cross into Pakistani airspace to target Afghan refugees camps in Pakistan. In order to counter the Soviet jets, United States started providing F-16 jets to Pakistan. These F-16 jets lacked the capability to fire radar-guided beyond-visual range missiles and thus required to get close to their opponents in order to use their AIM-9P and more advanced AIM-9L Sidewinder heat-seeking or their 20-millimeter Vulcan cannons. On 17 May 1986, two Pakistan Air Force (PAF) F-16 intercepted two Su-22M3K belonging to Democratic Republic of Afghanistan Air Force (DRAAF) near the Pakistani airspace. Pakistani officials insisted that both the fighter jets belonging to DRAAF were shot down while Afghan officials confirmed loss of only one fighter jet. Following the engagement, there was major decline in the number of attacks on Afghan refugees camps in Pakistan. On 16 April 1987, a group of PAF F-16s again chased down two DRAAF Su-22 and managed to shoot down one of them and capture its pilot. In the year 1987, Soviet Union reported that Pakistani fighter jets were roaming in Afghan airspace, harassing attempts to aerial resupply the besieged garrisons like the one in Khost. On 30 March 1987, two PAF F-16s shot down an An-26 cargo plane, killing all 39 personnel on board the aircraft. In the coming years, PAF claimed credit for shooting down several Mi-8 transports helicopter, another An-26 which was on a reconnaissance mission in 1989. In the year 1987, two PAF F-16 ambushed four Mig-23 who were bombing Mujahideen supply bases. In the clash, one PAF F-16 was lost after it was accidentally hit by an AIM-9 Sidewinder fired by the second PAF F-16. The PAF pilot landed in Afghanistan territory and was smuggled back to Pakistan along with wreckage of his aircraft by the Mujahideen. However, some Russian sources claim that F-16 was shot down by Mig-23, though the Russian Mig-23 were not carrying air-to-air missiles.