As Hezbollah renewed cross-border attacks on Israeli troops Monday, drawing Israel's retaliation, its leader warned a wider confrontation was possible but said the Lebanese guerrilla group was focusing for now on a disputed border area.

Hours after Sheik Hassan Nasrallah's speech in the capital, Beirut, rockets were fired from southern Lebanon toward the Israeli border town of Kiryat Shemona. Three booms jolted the nighttime silence, followed by the sound of Israeli warplanes flying overhead.

But Syria's U.N. ambassador told the Security Council on Monday that Lebanon has confirmed "at the highest level" that it has no intention of opening a new front in the Mideast conflict.

Syria is the main power in Lebanon and Ambassador Mikhail Wehbe's statement followed warnings from Israel and the United States that attacks by Hezbollah guerrillas from south Lebanon across the U.N.-drawn boundary with Israel threaten to widen the Israeli-Palestinian conflict.

In Israel, security sources said three Katyusha rockets landed in open fields in the Upper Galilee, but there were no reports of casualties. The army said it was checking the report.

There was no word on who fired the rockets, the latest in several attacks that no one has claimed responsibility for in recent days. Lebanese authorities have arrested nine Palestinians in the earlier attacks.

Lebanese Hezbollah, which usually claims responsibility for its own actions, earlier Monday said its fighters attacked six Israeli positions in the Chebaa Farms area, a disputed stretch of farmland on Lebanon's border with the Israeli-occupied Syrian Golan.

An Israeli warplane retaliated with three rockets at the outskirts of the Lebanese village of Kfar Chouba. Israeli guns also shelled other areas in the vicinity, including near the village of Ghajar, which is partly in Lebanon and partly in the Israeli-occupied Golan.

Israeli warplanes also blasted targets near the town of Hasbaya, about 10 miles north of the Israeli border and about 5 miles north of Israeli positions in Chebaa Farms. Guerrillas fired at least one surface-to-air rocket at an Israeli jet. There was no word on casualties.

The strike was the deepest in Lebanon since July 1, when Israeli warplanes hit a Syrian army position in the Bekaa Valley near the Syrian border, accusing Damascus of supporting the guerrillas.

The sharp escalation in the conflict during the past few days has led American, U.N. and European Union diplomats to warn Israel and Lebanon of the danger of reviving the war along their border. The border had been largely quiet since Israeli troops withdrew from southern Lebanon in 2000, ending an 18-year occupation.

The violence has flared as Israel pressed its offensive against Palestinians in the West Bank.

Hezbollah leader Nasrallah said Palestinians were appealing to his group to enter the fighting to help them relieve the pressure from the Israeli incursion in the West Bank. But he said for now, he will continue to exercise restraint and limit the fighting to the Chebaa Farms area.

Nasrallah, speaking to about 2,000 supporters at an underground conference hall in the Hezbollah stronghold of south Beirut, speculated Israeli Prime Minister Ariel Sharon could be planning mass expulsions of Palestinians, which could provoke more intense fighting.

"We must keep weapons for this," Nasrallah said.

Hezbollah is believed to possess hundreds, perhaps thousands, of Katyusha rockets that can strike deep inside Israel. Israel has accused Iran, Hezbollah's main backer, of supplying thousands of long-range rockets to the Shiite Muslim group for the purpose of striking deep inside Israel's heartland. Usually, such missiles have a range of up to 13 miles.

The guerrillas have used Katyusha rockets on numerous occasions during the Israeli occupation of southern Lebanon.

"We should be prepared to face the worst. ... We keep this choice (of weapons) for the worst-case scenario," he said.

Turning to the United States, which labeled Hezbollah a terrorist organization, Nasrallah said Washington was a "full partner" with Israel in attacks on Palestinians. He said the Americans had the power to bring about a cease-fire, but did not want to.

But according to the Israeli defense ministry troops plan to pull out of the West Bank towns of Qalqiliya and Tulkarem early Tuesday. The announcement came two days after President Bush urged Israel to start pulling its troops out of the West Bank without delay.

On Monday, Israel called up additional reserve units to serve near the border. A day earlier, fighting between the Israeli army and Lebanese guerrillas injured seven soldiers and sent residents of northern Israeli into bomb shelters for an hour.

Lebanese President Emile Lahoud discussed the situation in the south with Prime Minister Rafik Hariri. A Presidential Palace statement quoted Hariri as saying the efforts were focused on contacts taking place to solve the situation in south Lebanon. It gave no details.

Although the government has backed Hezbollah's claim to Chebaa Farms, officials have recently cautioned against expending the conflict so not to give Israel the pretext of striking deeper into Lebanon.