Two teenaged Palestinian guerrillas attempting to fly into Israel in a hot-air balloon before dawn today were shot down and killed by Israeli forces. Hours later Israeli warplanes bombed suspected guerrilla targets in southern Lebanon in apparent retaliation, killing and wounding a dozen persons.

Seemingly timed to coincide with the meeting of the Palestine National Council now under way in Damascus, the balloon raid was carried out by the radical, Libyay-backed Palestine Liberation Front.

Israeli military spokesmen said the balloon was carrying arms and explosives and was shot down while still over Lebanon. PLF Leader Abu Abbas in Damascus said the balloon landed far inside Israel near the city of Kiryat Shmona but U.N. observers concurred with the Israeli version.

The two balloonists had documents saying their mission was to seize hostages and demand the release of 15 Israeli-held guerrillas, including two of their comrades who had tried to infiltrate on motorized hang gliders five weeks ago, the Israeli military said.

The balloon was a blue 56 Bolt model made by Tunder Balloons of London, military sources said, and the guerrillas carried an M16 automatic rifle, a submachine gun, a Kalashnikov automatic rifle and an antitank weapon.

The two guerrillas survived the crash that shattered the balloon gondola, and Israeli troops chased them through rocky terrain. They were killed in a brief battle, the military said.

They said the Balloon was shot down at 4 a.m. near the Lebanese village of Houle , across the border from the Israeli kibbutz of Manara.

Although Abul Abbas said the raid showed the fallacy of Israel's "so-called secure borders," analysts have noted that in fact the heavy Israeli ground defenses have made any but aerial operations all but impossible.

The PLF, which is hoping in Damascus to win a seat at the reorganized executive committee of the Palestine Liberation Organization, also claimed responsibility last month for the operation involving two motor-driven hang gliders.

One glider successfully negotiated the border, but its two-man crew was captured by the Israelis in northern Israel after a brief chase. The other crashed in southern Lebanon in territory controlled by pro-Israeli Christian Lebanese militias and was turned over to the Jewish state.

In the apparent relatiatory Israeli air raids today, 12 persons were killed or woulded in and around the southern port city of Tyre.

Eyewitnesses said Palestinian ground fire -- including surface-to-air missles fired from shoulder-held launchers -- forced the Israeli was-planes to drop their bombs from a high altitude.

It was the second Israeli air strike in a week. Amereican-built Israeli Phantoms bombed Palestinian positins only 12 miles of Beirut last Thursday. p

Meanwhile, in East Beirut, Christian leader Bashir Gemayel said at a news conference he was ready to negotiate with the Syrians whose troops have inflicted a major military defeat on the rightist Lebanese forces in the eastern city of Zahle.

He implicity acknowledged Israeli military aid, and said some unidentified Arab states had helped as well.

Jordan's charge d'affaires in Beirut, Hisham Moheisen, arrived in Amman from Damascus after being released by kidnapers who held him for 66 days in Lebanon.

Before leaving Damascus, he told reporters he had met with Syrian President he had met with Syrian President Hafez Assad to thank him for helping secure his release.

The official Syrian News Agency reported Tuesday from the east Lebanese town of Shtoura that Moheisen, 42, had been handed over to the Syrian peacekeeping force, which has its headquarters there. He arrived in Damascus that night.