Jerusalem ? Israel declared Tuesday it was ready to fight Hezbollah guerrillas for several more weeks, raising doubts about international efforts to broker an immediate cease-fire in the fighting that has killed more than 260 people and displaced 500,000. The military said early today it sent some troops into southern Lebanon in search of tunnels and weapons.

Despite the diplomatic activity, Israel is in no hurry to end its offensive, which it sees as a unique opportunity to crush Hezbollah. The Islamic militants appear to have steadily built up their military strength after Israel pulled its troops out of southern Lebanon in 2000.

Israeli warplanes struck an army base outside Beirut and other areas in south Lebanon on Tuesday, killing 27 people, and Hezbollah rockets battered Israeli towns, killing one Israeli. Five big explosions reverberated over Beirut early today, and missiles hit towns to the east and south of the capital.

At daybreak today, a small number of Israeli troops were operating just across the border inside southern Lebanon, looking for tunnels and weapons, the Israeli military said without providing any more details.

The incursion came a day after Israel indicated that it might send large numbers of ground troops into the southern Lebanon, but Israel’s U.N. Ambassador Dan Gillerman denied today’s operation was part of any such operation.

“What is going on at the moment is a number of Israeli ground troops very near to the border on the Lebanese side, trying to destroy some Hezbollah outposts,” he told CNN.

Israelis play on the beach at a camp in southern Israel constructed for residents who fled their houses in northern Israel. Arkady Gaydamak, one of Israel's most high-profile and controversial businessmen, erected the compound within 24 hours, shelling out some 00,000 for tents, food and entertainment for 5,000 people who fled their battered homes in northern Israel trying to escape the unprecedented rocket barrage pounding their towns in the past week.

“This is an operation which is very measured, very local,” he said. “This is no way an invasion of Lebanon. This is no way the beginning of any kind of occupation of Lebanon.”

Israel’s forecast of a lengthy campaign, coupled with President Bush’s evident reluctance to bring pressure on Israel to agree to a cease-fire, seemed to quash any hopes for an early resolution of the crisis, now entering its second week.

Families in southern Lebanon, the site of most Israeli airstrikes, drove north on side roads, winding among orange and banana groves and waving improvised white flags from their car windows.

In an interview with the BBC, Lebanese Prime Minister Fuad Saniora said Israel is “opening the gates of hell and madness” on his country. He urged Hezbollah, which is backed by Syria and Iran, to release two captured Israeli soldiers but said Israel’s response had been disproportionate.

Bush said he suspects Syria is trying to reassert influence in Lebanon more than a year after Damascus ended what had effectively been a long-term military occupation of its smaller, weaker neighbor.

“We have made it very clear that Israel should be allowed to defend herself,” Bush said in Washington. “We’ve asked that as she does so that she be mindful of the Saniora government. It’s very important that this government in Lebanon succeed and survive.”

Israeli Prime Minister Ehud Olmert blamed Iran for sparking the clashes between Israel and Hezbollah, saying the country was trying to distract the world from the controversy over its nuclear program.

The offensive was sparked by the soldiers’ capture July 12 but has now broadened into a campaign to neutralize Hezbollah.

“I think that we should assume that it will take a few more weeks,” Maj. Gen. Udi Adam, head of the army’s northern command, told Army Radio.