JERUSALEM -- An agreement that had limited fighting in southern Lebanon appears on the verge of collapse after Hezbollah guerrillas shelled northern Israel in retaliation for Israeli attacks in Lebanon.
The collapse of the understanding could lead to a large-scale bombardment of Lebanese towns similar to the one Israel carried out in 1993.
At least three Lebanese and two Israelis have died since Friday in the tit-for-tat shelling spilling over both sides of the southern Lebanon zone occupied by Israeli troops.
Lebanese guerrillas fired small rockets across the zone and into northern Israel Friday night, the first such widespread shelling since July 1993. A 17-year-old youth jogging on the beach was killed by a rocket, and about 12 others were wounded slightly -- mostly by flying glass.
The attack was prompted by Friday's assassination in Lebanon of an Hezbollah leader whose car was rocketed by an Israel Cobra helicopter. An aide in the car also died.
An Israeli soldier was killed in the fighting Friday, and a Hezbollah guerrilla died yesterday of wounds.
Israeli Prime Minister Yitzhak Rabin, touring the northern towns that were shelled, said yesterday that he had requested U.S. help to restore the Hezbollah pledge not to attack Israeli towns.
If that pledge is not kept, Mr. Rabin warned, "it will make a need on the part of Israel to take actions which I will not elaborate about" -- an unveiled threat of retaliation.
But leaders of the Hezbollah -- Party of God -- said in Beirut that its fighters would continue to shell civilian areas in Israel as long as Israel shells civilians in Lebanon.
Hezbollah has "a deep commitment to the principle of replying in kind and not to sit silent when villages are targeted," Hezbollah Sheik Nabil Qawooq said in Beirut.
The fighting spotlights the long-running, low-scale warfare in southern Lebanon. Israel invaded the country in 1982 and then withdrew to a narrow strip in southern Lebanon that it calls its "security zone."
The Hezbollah guerrillas, backed by Iran and with the approval of Lebanon and Syria, are fighting to expel Israel from that zone.
In July 1993, Israel launched a weeklong bombardment of Lebanese towns and villages north of the zone, killing an estimated 130 people, demolishing hundreds of homes and forcing several hundred thousand civilians to flee. To stop the bombardment, the United States helped broker an agreement to confine the fighting to the zone.
The details of that agreement were never released to the public, but Mr. Rabin acknowledged its outline yesterday: "In essence, these understandings are to limit the activities to the security zone . . . as long as civilian targets are not attacked intentionally by us" or by Israel's paid militia, the South Lebanese Army.
Israel, however, has frequently shelled towns and villages north of the zone, alleging that they are "terrorist targets." In addition, Israeli gunboats have for the past two months roamed far up Lebanon's Mediterranean coast, enforcing a blockade that kept Lebanese fishermen away from their fishing areas.
On Friday, Hezbollah guerrillas attacked an Israeli post on the northern edge of the occupied zone, killing one soldier. Israel responded by shelling several Lebanese towns north of the zone. Israel also sent a helicopter gunship to fire an air-to-ground missile on a Mercedes car carrying a Hezbollah officer southeast of Tyre, Lebanon.
The missile destroyed the car, killing Hezbollah leader Ruda Yassin and an aide. An Israeli minister, Binyamin Ben- Eliezer, confirmed Friday that the attack had been planned.
In response, Hezbollah began shelling Israeli military targets in the occupied zone and fired an estimated 15 Katyusha rockets into civilian areas within Israel itself. Many Israeli civilians in the border towns have the spent the past two nights in bomb shelters.
JTC Hezbollah leaders said the Katyusha attack was in response to Israeli "aggression." Hezbollah chief Sheik Hassan Nasrallah said Beirut that Israel had killed 16 civilians this year, bombarded 75 villages and damaged 212 homes.
Mr. Rabin called the Hezbollah Katyusha attack a "total violation of the understandings."