IBL EL-SAQI, Lebanon (AP) – Israel took control of the strategic southern hub of Marjayoun on Thursday and warned that its fight against Hezbollah could grow wider and more severe if diplomacy fails.

Israeli leaders have authorized a major new ground offensive going deeper into Lebanon but have held off to give international negotiators more time.

The U.S. ambassador to the United Nations, John Bolton, said progress was being made on the diplomatic front and a Security Council vote on a cease-fire resolution could be held on Friday. The United States and France have been trying to bridge differences over a timetable for an Israeli withdrawal from Lebanon.

But in a clear signal that Israel was gearing up for a major push northward, Israeli warplanes blanketed downtown Beirut with leaflets threatening a “painful and strong” response to Hezbollah attacks.

Defense Minister Amir Peretz also said the military would use “all of the tools” to cripple the Islamic guerrillas if U.N. efforts toward a cease-fire pact collapse.

Earlier, missiles from Israeli helicopter gunships blasted the top of a historic lighthouse in central Beirut in an apparent attempt to knock out a broadcast antenna for Lebanese state television.

The seizure of the mostly Christian city of Marjayoun and nearby areas overnight appeared to be an attempt to consolidate bases and give Israel an important foothold in southern Lebanon before any possible push northward.

The planned offensive would thrust toward the Litani River valley, 18 miles north of the border _ and would be aimed at crippling Hezbollah before a possible cease-fire.

Top U.N. humanitarian official Jan Egeland, meanwhile, criticized Israel and Hezbollah for hindering the delivery of aid to civilians trapped in southern Lebanon, saying it was a “disgrace” they had failed to allow convoys to get through.

Egeland said a plan worked out with Israel, Lebanon and Hezbollah to funnel aid through humanitarian corridors has not worked the way each side had promised.

“The Hezbollah and the Israelis could give us access in a heartbeat,” Egeland said at the U.N.’s European headquarters in Geneva. “Then we could help 120,000 people in southern Lebanon. I don’t think that any military advantage has been gained in these last days or will be gained in the next few hours.”

At least 715 people _ most civilians _ have been killed in Lebanon since fighting erupted July 12 after a cross-border raid in which Hezbollah captured two Israeli soldiers. The Lebanese government’s Higher Relief Council put the number higher _ at 973.

Authorities in Israel said 120 Israelis have been killed, including 82 soldiers and 38 civilians. Israel suffered its worst one-day military losses on Tuesday, with 15 soldiers killed, most in other areas of the south away from the Marjayoun area.

Taking command of Marjayoun was not considered a key battlefield victory since the city gives little support to Hezbollah. But reaching the site required passing through Hezbollah country, the scene of fierce fighting. Witnesses said they saw hundreds of Israeli foot soldiers moving into the town Thursday afternoon.

Hezbollah claimed it destroyed 13 Israeli tanks. Israel did not immediately give a tally of its losses.

Lebanon’s Interior Minister Ahmed Fatfat also said Israeli troops had commandeered a garrison in Marjayoun and detained some 350 Lebanese soldiers and police inside after they refused to share the building, but Israel dismissed the claim.

“The troops refused and said they would leave, but the Israelis did not let them,” Fatfat said, adding the head of the local force Brig. Gen. Adnan Daoud was among the detainees.

In Israel, a military spokeswoman said troops arrived at a building in the town, where there were soldiers, police and refugees. The Israelis advised them to remain there for their own safety as fighting all around but they are not being detained by force. “Nobody has been taken prisoner,” she said, speaking on condition of anonymity because military rules did not allow her to make public comments.

Marjayoun _ about five miles from the Israeli border _ was used as the command center for the Israeli army and its allied Lebanese militia during an 18-year occupation of southern Lebanon that ended in 2000. The high ground around the town overlooks the Litani River valley, one of the staging sites for the relentless Hezbollah rocket assault on northern Israel.

Israeli gunners used their new vantage points as payback: pounding Hezbollah-led areas such as the plain around the nearby town of Khiam, which has been used as a rocket site for the militants.

Still, Hezbollah was defiant. It fired 110 rockets into northern Israel by mid-afternoon, including one that hit Haifa, Israeli police said. An Arab Israeli mother and her young daughter were killed in the village of Deir al-Assad. Lebanese officials reported at least four civilian deaths Thursday.

On Wednesday, Hezbollah leader Sheik Hassan Nasrallah warned in a television address that Israeli Arabs in Haifa should flee for their own safety and threatened more strikes on the port city, already hit repeatedly by Hezbollah rockets.

In Ibl el-Saqi, a village about two miles east of Marjayoun, the mayor said nearly all residents had fled to the north.

“They all left this morning. There was very intense shelling last night,” Riad Abou Samra said.

But it seemed fewer and fewer areas of Lebanon were safe from the threat of Israeli attacks, including the relatively untouched heart of Beirut.

The leaflets that fluttered down over the capital Thursday said “the Israeli Defense Forces intend to expand their operations in Beirut.” They said the decision came after statements from “the leader of the gang” _ an apparent reference to Nasrallah’s television address.

Israel also extended its warnings to areas north of Beirut. Leaflets said trucks “of any kind” would face attack after 8 p.m. along the northern coast road to Syria.

A round-the-clock road curfew has been in force across southern Lebanon since early Tuesday.

Israeli warplanes pounded a coastal highway junction connecting three major southern cities _ Sidon, Tyre and Nabatiyeh. The junction already had been nearly cut off in strikes on July 12 _ the first day of fighting _ which spared only a single lane. It was not clear if the road was completely severed in Thursday’s hits.

The strike at the historic lighthouse, built early last century during French colonial rule, was the first in central Beirut since a warning Aug. 3 by Nasrallah that such a move would bring retaliation against Tel Aviv.

The capture of Marjayoun came just hours before a senior Israeli official, Rafi Eitan, announced the delay of an expansion of the ground offensive to give U.N. diplomats time for a cease-fire deal. Lebanon and its Arab allies demand Israel withdraw its forces as part of any cease-fire.

The offensive is expected to last a month and eliminate 70 to 80 percent of Hezbollah’s short-range rocket launchers, but not its long-range launchers, senior military officials said.

However, Trade Minister Eli Yishai, who abstained in Wednesday’s vote, said the assessment is too optimistic. “I think it will take a lot longer,” he said.

Israel is waiting to see whether Arab and Western diplomats can find a solution to end the monthlong conflict.

“There are diplomatic considerations. There is still a chance that an international force will arrive in the area. We have no interest in being in south Lebanon. We have an interest in peace on our borders,” Eitan told Israel Radio.

The U.S. ambassador to Lebanon, Jeffrey Feltman, met three times Thursday with Prime Minister Fuad Saniora, whose aides reported no progress on negotiations to find a cease-fire.