From this "resistance fortress" of southern Lebanon, as a Shiite Moslem leader described a 7-square-mile triangle comprising five villages northeast of Tyre, Amal guerrillas are attacking and killing an increasing number of Israeli troops.

Before the Israeli invasion of June 1982, these villages and their 15,000 residents were in the forefront of the fight against the Palestinian guerrillas who occupied southern Lebanon. They greeted the Israelis with the traditional welcome of rose water and rice.

But as Amal's top leader, Nabih Berri, predicted a month later, unless the Israelis left Lebanon, they would face a Shiite opposition "100 times worse than the Palestinians."

At first, the Shiites' resistance was passive -- boycotting Israeli products, isolating Israeli agents, preventing their own young men from joining Israeli-backed militias.

The turning point came last June, said Daoud Daoud, an Amal resistance leader here, when, he charged, plainclothesmen of the Israeli secret police shot and killed three local Amal leaders in separate incidents. Israeli officials have denied involvement in the three killings.

"The message was simple," Daoud said: "You either join us or be killed."

As Daoud sees it, the Israelis had set off the time-tested cycle of violence and counterviolence, a formula that could only favor the Lebanese.

Starting in midsummer, attacks against Israeli troops, previously centered around Sidon and Nabatiye, north of the Litani River, moved south to this area.

The resistance has increased since Saturday, when the Israelis carried out the first of three promised withdrawals. The Amal campaign is distinct from that of the pro-Iranian Hezbollah fundamentalists, whose show of force in Sidon on Monday was sternly condemned by Amal leader Berri.

The latest blows and counterblows in the cycle of violence centered on Bazuriye, 4 miles south of here, where an Israeli major and sergeant were killed by roadside explosions earlier this week. This morning, Israeli forces responded by sending 20 armored personnel carriers into the village, in line with calls at home for a new "get tough" policy to limit casualties here.

What took place there is in dispute. As has happened before, widely differing versions were issued by the Israeli military and the United Nations peace-keeping force whose French contingent was present in the village.

The Israelis said that two armed men were killed while attempting to escape, a third was captured and AK47 assault rifles and rocket-propelled grenades were confiscated from them.

U.N. spokesmen said the Israelis rounded up about 200 men for questioning and bulldozed a house. Later a man was found dead just outside the village with three bullets in the head and three men were wounded, one seriously. The spokesmen said the Israelis, unusually, had denied a U.N. request to send a medical evacuation helicopter for the wounded villagers, who were later taken by ambulance to the U.N. hospital in Naqura on the Mediterranean coast.

Nothing that happened in Bazuriye surprised Daoud. He, fellow leaders and many other Lebanese from this part of southern Lebanon say they know about the Israelis.

They repeat stories of allegedly unprovoked shootings by Israeli soldiers -- stories which, though unverified and denied by Israeli officials, are widely believed here.

They say they are convinced that the Israelis are nervous, scared, spread too thin to exercise effective control and determined not to join the more than 600 Israeli soldiers who have died in Lebanon since the 1982 invasion.

Daoud said the Israelis should be aware that the resistance was "no summer cloud which would go away."

Last Thursday, Israeli troops came once again to this hill town 20 minutes by taxi from Tyre.

Dr. Ali Jabber walked around this town of 2,000 inhabitants barely containing his fury.

"They put police dogs in the mosque and the husseineyeh," an adjacent meeting hall, he charged, "and played disco music over the mosque loudspeaker system."

Dogs are considered filthy by many Arabs.

"They tore pages from the Koran," he said, pointing to loose sheets now carefully stacked in a corner of the mosque, "and robbed the collection box for the poor."

"They also ransacked my surgery," he added. "And look at my new window," he said, pointing to an enormous hole in its outside wall. "And they even stole the Boy Scouts' musical instruments."

Across the main square, the wall of the secondary school was smashed by a bulldozer, as were two cars, he noted. The windows of the classroom doors were broken.

Down in the courtyard where the doctor said the soldiers herded the villagers together for interrogation, the name Ali Kharis was written in red ink on a wall.

"Abu Ghazala," as the Israeli secret police chief in Tyre is called, "asked us to kill Kharis ourselves or say where he lived," the doctor recounted. "But we all said, 'We are Ali Kharis.' "

The Israelis also shot and killed a farmer, Ali Maaz, who wandered into the village from his fields apparently unaware of the Israeli order to gather in the schoolyard, the doctor charged.

French troops patrolling as part of the U.N. peace-keeping force scuffled with the Israelis. The doctor said they intervened after the Israelis hit a four-month-old child with a rifle butt and fired at a boy.

"For every action," Daoud, a former physics teacher, said in his best schoolmaster fashion, "there is an equal and opposite reaction."

Listening to Daoud didactically explain how the villagers of Bedias, Burj Rahhal, Maarakeh, Youra and Yanouh came to form the nucleus of the southern resistance is like hearing a recitation of how to commit every mistake in an antiguerrilla warfare handbook.

The villagers' initial joy when the Israelis drove out the Palestinians in 1982 turned to growing suspicions when the Israelis started recruiting local youths into a succession of constantly changing militias -- the Free Lebanese Army, the National Guard, the Shiite Army or, finally, the South Lebanon Army.

Fearful of this indirect occupation, Amal warned the Israelis that their shared desire for law and order in the south was best served by allowing the Lebanese Army and the U.N. peace-keeping force to go right down to the Israeli border.

The Israelis, using Lebanese surrogates, have maintained a presence in the border strip since 1976 and, since 1978, have done so in defiance of U.N. Security Council resolutions.

"Had we gone along," Daoud said, "that would have been the end of Lebanon. Syria would keep the Bekaa Valley in the east and Tripoli in the north. The rest of the country would be divided into cantons for the various communities."

"We refused," he added, "because we wanted a unified, central government."

Although Daoud has been on the Israeli occupation forces' most wanted list for eight months, last August he was still denying to a Washington Post correspondent that he was involved in the resistance movement. The open involvement of Amal leaders like Daoud today is a measure of how much things have changed.

In January, security sources reported 110 operations against the Israelis. There have been 80 reported so far this month. Meanwhile, attacks against the South Lebanon Army have led to such massive desertions that specialists question its combat effectiveness.

"The Israelis claim 70 to 80 percent of the attacks originate from here," Daoud said as Israeli Air Force planes droned overhead. "This is the first time Israel is facing a people's war. They are stronger in qualified soldiers, tanks and planes but our faith is stronger."

Amal has organized the villagers. Some keep watch on the Israelis to pass word whenever their Army moves. Within minutes, peaceful villages are transformed into a maze of stones and burning tires, blocking the streets. Men, women and children brave the Israelis in the open, throwing stones and shouting insults.

Every time the Israelis come -- and Daoud said there were four big operations and 10 times as many smaller ones in three of the five villages -- the 30 men on their wanted list have managed to escape. Daoud said he had slept in his clothes for the past six months to keep ahead of them.

The Israelis know whom they are looking for, thanks in large part, Daoud said, to collaborators who previously had worked for the Palestinians when Amal was fighting the guerrillas.

Yet Daoud and other leaders were insistent that the Israelis are wrong in claiming Amal plans to continue fighting them even after the Israel Army leaves Lebanon.

In the meantime, Amal leaders feel they have the upper hand, especially now that they have killed or frightened off most of Israel's Lebanese collaborators, thus depriving their enemy of vital intelligence.

"The Israelis were famous for their intelligence coups -- stealing the gunboats from Cherbourg under the nose of the French, kidnaping Adolf Eichmann, the Entebbe raid freeing the airline passengers, stealing the radar from the Egyptians," Daoud said. "But they have failed here."

"We have destroyed their myth that Israel is the world's fourth military power," he said.

"We have done it ourselves, without being paid like the Palestinians and without being helped by other Arabs. In all the Arab world no one has resisted like us."

In Tyre, a merchant put it another way. "Had the Israelis left after three months we would still think they were giants," he said. "But now it is open season on them and even old men want to become martyrs."