Pakistani Air Force officers displayed wreckage today from an Afghan war plane shot down over Pakistan yesterday and said they are still searching for the fuselage and the pilot, who they presumed was killed.

In the western Pakistani town of Parachinar, officers showed journalists sections from the tail of what they said was a Soviet-built Su22 ground attack plane, evidence of the first officially confirmed aerial battle between Afghanistan and Pakistan.

They also described the 9 1/2-minute incident in which it was shot down and a similar Afghan warplane damaged after having violated Pakistani airspace.

The incident occurred over Pakistan's Kurram district, where Moslem Afghan resistance fighters have bases for their battle against Soviet and Afghan government forces across the border in eastern Afghanistan. The Soviets are leading an offensive on the Afghan side of the border to destroy guerrilla supply routes from Pakistan into the Afghan interior.

Two Pakistani air vice marshals, Hakimullah and Mohammed Younis, said they presumed that the downed plane's pilot might have been either Soviet or one of the better trained Afghan pilots in the Afghan Air Force. They told journalists that the pilot had had little chance to bail out because the plane broke up as it was hit, with the fuselage spinning into the rocky mountains surrounding Parachinar.

The Pakistani government summoned the Afghan charge d'affaires today to receive a formal but routine protest over the incident.

The Pakistani Air Force flew a group of journalists to Parachinar, about 170 mile east of here, in a military helicopter, to buttress their account of yesterday's engagement. Afghanistan today remained silent on the matter.

Pakistani and western journalists said the officers displayed parts of the plane's tail fin, exhaust cowling, and the drag parachute used to help brake the plane on landing. The parachute had deployed when the plane was hit, leading to reports that the pilot had bailed out before the crash.

Hakimullah said two U.S.-built Pakistani F16s on routine patrol had intercepted the two Su22s, after they had flown almost 10 miles into Pakistani airspace. The Afghan planes at first had turned back to Afghanistan, but when the F16s began to catch up with them, they turned to fight, he said.

The Soviet Sukhoi series of planes is designed to attack ground targets, rather than opposing aircraft, and has been a main instrument in recent offensives against the guerrilla supply routes from Pakistan.

In the engagement yesterday, a Pakistani jet fired two U.S.-made Sidewinder missiles, the second of which destroyed one Sukhoi, and then hit the other with machine-gun fire, Younis said. He said the damaged Sukhoi, trailing smoke, had crossed back into Afghanistan, and disappeared from Pakistani radar screens, presumably crashing.