Israeli paratroopers and naval commandos launched a pre-dawn attack on the Lebanese coast yesterday, destroying a Palestinian sea base and killing at least eight Fatah guerrillas about 13 miles north of the Israeli border.

The attack, during which two Israelis were killed and eight others injured, came just four days before the last of the Israeli troops in southern Lebanon are scheduled to withdraw.

Israeli military officials said the raiders landed from the Mediterranean and completed the attack in just 15 minutes. They said it was ordered because of intelligence information that a terrorist attack on an Israeli civilian target was to be conducted within a matter of days.

The guerrilla base, a small facility located at Dahar el Burj, six miles south of Sidon, was the debarkation point for an attack three years ago on Tel Aviv's Savoy Hotel, in which six Israelis were killed, military officials said.

In Beirut, a PLO spokesman said the Israeli attack was mainly in retaliation for recent Palestinian attacks inside Israel, special correspondent William Branigin reported. A PLO statement termed the raid "a complete failure" and said the Israelis were "attempting to cover up the size of their heavy losses."

But the Palestinian news agency WAFA offered no casualty figures, and hospitals in the area reported nine guerrillas killed and 17 Palestinians and Lebanese civilians injured.

Israeli officials said the attack was not in reprisal for the terrorist bombing of a civilian bus in downtown Jerusalem a week ago, and that the timing of the strike inside Lebanon was prompted solely by the imminence of a guerrilla raid being launched from the base.

But Israeli government sources noted that a side effect will be to demonstrate to the Palestine Liberation Organization that even after Israel withdraws from southern Lebanon it will be willing to make pre-emptive strikes to prevent terrorist raids inside Israel.

The attack is certain to prompt a spate of condemnations and possibly resolutions in the United Nations, as occurred after Israel invaded southern Lebanon on March 14 in reprisal for the Palestinian terrorist attack three days earlier on a tourist bus on a coastal raid near Tel Aviv.

But a spokesman for the U.N. peace keeping force headquarters in Jerusalem said yesterday that no complaints of cease-fire violations had been received. Lt. Gen. Ensio Siilvasvuo, the Finnish commander of the U.N. peacekeeping force in the Middle East, went to Beirut yesterday, a day earlier than scheduled for a meeting with Lebanese Defense and Foreign Minister Fuad Butros.

Branigin reported from Beirut that while PLO sources suggested that the Israeli raid was designed as an excuse to push back the June 13 withdrawal deadline, Western diplomats dismissed that view. "They're just getting a couple of licks in before they leave," one Western military attache said.

U.N. officials noted, that Siilvasvuo and Butros have been meeting regularly in recent weeks to discuss the conditions of Israel's withdrawal from southern Lebanon on Tuesday.

Israeli government sources said the Dahar el Burj attack apparently was intended as a swift and precise operation to avoid any Israeli casualties - partly in consideration of public opinion among war wary Israelis - and they noted that all of the army casualties resulted from the explosion of a small building which the commandos did not know contained explosives.

Landing from the sea in the early morning darkness, the raiders stormed the six on-end-one-half story buildings in the compound, which is located between a railway line and a highway skirting the coast, army officials said.

An Israeli military spokesman said all of the building were destroyed, and that the commandos and para-troopers captured a cache of weapons, including American-made M-16 rifles with grenade launchers.

The army said the two Israelis were killed when a wall collapsed as a result of the munitions shed explosion.

Military officials said that between 30 and 40 guerrillas were believed to have been at the base, which is the type that normally maintains small craft and motor-powered rubber dingies used in the March 11 raid on the coastal road between Haifa and Tel Aviv in which 36 civilians died.

It was from another guerrilla base, at Damur about 20 miles south of Beirut, from which that raid began.

Israeli authorities said seven of the eight Israeli wounded were slightly injured, and that four of those had to be evacuated by helicopter. The remainder made it back to Israel by seat with the rest of the force.

Officials said that Fatah seabased units, trained in Libya and Iraq, are equipped with speedboats, rubber dingies, diving equipment and underwater mines, as well as automatic weapons.

When Israel launched its March 14 air and sea invasion of southern Lebanon, the government announced that the purpose was to root out terrorist bases from which strikes inside Israel originated.

Later, it was disclosed that Israeli commando units operating from the Mediterranean had raided the Damur PLO base several weeks before the Tel Aviv coastal road assault, after obtaining intelligence information that such a terroirst raid was pianned.

Observers suggested yesterday that the Dahar el Burj attack by the Israelis may cause some internal conflict within Fatah and other PLO units because PLO leader Yasser Arafat has recently attempted to order restraint in southern Lebanon in the face of demands for increased military action by leaders of radical splinter groups.

TTS - Deremer

In his dispatch from Beirut, Branigin said that the Israelis had destroyed two motor launches and three buildings belonging to the guerrillas. One building contained arms, ammunition and food supplies for the coastal base, which was manned by about 20 Fatah Members.

The consensus in Beirut was that the raid was a warning to the Palestinians not to try any new sea attacks since they remain vulnerable even after the Israeli withdrawal.

The attack came only a few miles south of Syrian positions at the Zahrani oil refinery. Political sources in Beirut viewed this as an embarrassment for the Syrians and perhaps as a deliberate warning to them not to move south after the Israeli withdrawal.