Israeli warplanes returning from an air raid on Palestinian guerrilla positions in South Lebanon shot down two Syrian Mig21s in an aerial battle today, according to the Israeli nilitary command.

It was the first time in four months that Israeli and Syrian aircraft engaged in a dogfight and followed by less than two weeks the killing of three Syrian soldiers during an Israeli Army attack on guerrilla positions in Lebanon.

The Israeli pilots reported there was no sign of parachutes from the downed Soviet-made Migs, which were shot down in Lebanese airspace about five miles west of the northern Israeli town of Metulla. All Israeli planes returned safely, the Army said.

[a Syrian communique, broadcast on the official Damascus Radio, acknowledged that two Syrian planes were hit and also reported two Israeli planes were shot down, one crashing into the sea and the other inside Israel, according to Washington Post special correspondent Nora Boustany in Beirut.]

Israeli military sources said the Migs, approaching from the northwest, intercepted a flight of Israeli warplanes returning from a bombing raid on Palestine Liberation Organization positions in the vicinity of Tyre, on the Mediterranean coast about 15 miles north of the Israeli border, and on Nabatiyeh, about 10 miles northwest of Metulla.

The military command refused to say what type of Israeli aircraft were invilved in the aerial battle. Such air raids in Lebanon normally are made by the U.S.-built F4 Phantoms and Israeli-made Kfir fighter-bombers, sometimes with the support of F15 fighter-bombers.

Air Force officials here said the positions at Tyre and Nabatiyeh were training bases shared by several guerrilla groups under the PLO umbrella organization and that the purpose of the air raid was to disrupt training for terrorist infiltration into northern Israel. They said the Israeli pilots reported "accurate hits" on the PLO bases.

Although Israeli aircraft have made a number of strikes inside Lebanon in recent months -- the last one was Nov. 7 -- the Syrians had not been sending up interceptors to challenge the Israelis. The last air clash occurred Aug. 24, when Israeli fighters shot down a Syrian Mig21 after what was described as a brief dogfight about nine miles east of Sidon, a Lebanese coastal town 30 miles north of the Israeli border.

On Sept. 25, 1979, Israeli F15s and Phantoms shot down four Migs south of Beirut. On June 27, 1979, in the first Israeli-Syrian dogfight since the 1973 war, Israeli F15s and Kfirs shot down fove Syrian Migs over the coast of southern Lebanon. Following those aerial battles, the U.S. State Department complained to Israel about use of F15s, which were sold to Israel in 1976 on condition that they be used only in self-defense.

[the State Department today deplored the latest air battle and called on both sides to exercise restraint "and avoid further armed action."]

Following a Dec. 18 Israeli Army ground assault in South Lebanon, in which three Syrian soldiers were killed, the Israeli government expressed its regret and Army officials went out of their way to stress that Israel is not interested in engaging the Syrians in Lebanon.