A ceasefire between Israel and Iran-backed group Hezbollah came into effect at 0200 GMT on Wednesday after U.S. President Joe Biden said both sides accepted an agreement brokered by the United States and France.

Bursts of gunfire could be heard across Beirut after the ceasefire took effect. It was not immediately clear if the shooting was celebratory, as gunfire had also been used to alert residents who may have missed evacuation warnings issued by Israel’s military.

Streams of cars carrying people displaced from southern Lebanon by Israeli strikes in recent months began heading back to the area after the ceasefire, according to Reuters witnesses.

The ceasefire promises to end a conflict across the Israeli-Lebanese border that has killed thousands of people since it was ignited by the Gaza war last year.

Biden spoke at the White House on Tuesday shortly after Israel's security cabinet approved the agreement in a 10-1 vote. He said he had spoken to Israeli Prime Minister Benjamin Netanyahu and Lebanon's caretaker Prime Minister Najib Mikati, and that fighting would end at 4 a.m. local time (0200 GMT).

"This is designed to be a permanent cessation of hostilities," Biden said. "What is left of Hezbollah and other terrorist organizations will not be allowed to threaten the security of Israel again.”

Israel will gradually withdraw its forces over 60 days as Lebanon's army takes control of territory near its border with Israel to ensure that Hezbollah does not rebuild its infrastructure there, Biden said.

"Civilians on both sides will soon be able to safely return to their communities," he said.

Hezbollah has not formally commented on the ceasefire but senior official Hassan Fadlallah told Lebanon's Al Jadeed TV that while it supported the extension of the Lebanese state’s authority, the group would emerge from the war stronger.

"Thousands will join the resistance ... Disarming the resistance was an Israeli proposal that fell through," said Fadlallah, who is also a member of Lebanon's parliament.

Iran, which backs Hezbollah, the Palestinian group Hamas as well as the Houthi rebels that have attacked Israel from Yemen, said it welcomed the ceasefire.

French President Emmanuel Macron said on social-media platform X the deal was “the culmination of efforts undertaken for many months with the Israeli and Lebanese authorities, in close collaboration with the United States.”

Lebanon's Mikati issued a statement welcoming the deal. Foreign Minister Abdallah Bou Habib said the Lebanese army would have at least 5,000 troops deployed in southern Lebanon as Israeli troops withdrew.

Netanyahu said he was ready to implement a ceasefire but would respond forcefully to any violation by Hezbollah.

He said the ceasefire would allow Israel to focus on the threat from Iran, give the army an opportunity to rest and replenish supplies, and isolate Hamas, the Islamist militant group that triggered war in the region when it attacked Israel from Gaza last year.

'SET IT BACK DECADES'

"In full coordination with the United States, we retain complete military freedom of action. Should Hezbollah violate the agreement or attempt to rearm, we will strike decisively," Netanyahu said.

Hezbollah, which is allied to Hamas, was considerably weaker than it had been at the start of the conflict, he added.

"We have set it back decades, eliminated ... its top leaders, destroyed most of its rockets and missiles, neutralized thousands of fighters, and obliterated years of terror infrastructure near our border," he said.

A senior U.S. official, briefing reporters on condition of anonymity, said the U.S. and France would join a mechanism with the UNIFIL peacekeeping force that would work with Lebanon's army to deter potential violations of the ceasefire. U.S. combat forces would not be deployed, the official said.

Jon Finer, deputy national security adviser in the Biden administration, told CNN that Washington would be watching for any violations of the deal.

"Implementation of this agreement will be key and we will be very vigilant to any attempts to disrupt what the two parties have committed to as part of this process today," he said.

Biden, who leaves office in January, said his administration would continue to push for an elusive ceasefire and hostage-release deal in Gaza, as well as for a deal to normalize relations between Israel and Saudi Arabia.

In the hours leading up to the ceasefire, hostilities raged as Israel ramped up its campaign of airstrikes in Beirut and other parts of Lebanon, with health authorities reporting at least 18 killed.

The Israeli military said it struck "components of Hezbollah’s financial management and systems" including a money-exchange office.

Hezbollah also kept up rocket fire into Israel.

Israel's air force intercepted three launches from Lebanese territory, the military said, in an extensive missile barrage on Tuesday night that led to warning alarms in about 115 settlements.

Alia Ibrahim, a mother of twin girls from the southern village of Qaaqaiyat al-Snawbar, who had fled nearly three months ago to Beirut, said she hoped Israeli officials, who have expressed contradictory views on a ceasefire, would be faithful to the deal.

“Our village – they destroyed half of it. In these few seconds before they announced the ceasefire, they destroyed half our village,” she said. “God willing, we can go back to our homes and our land."

A poll conducted by Israel's Channel 12 TV found that 37% of Israelis were in favour of the ceasefire, compared with 32% against.

Opponents to the deal in Israel include opposition leaders and heads of towns near Israel's border with Lebanon, who want a depopulated buffer zone on Lebanon's side of the frontier.

Both the Lebanese government and Hezbollah have insisted that a return of displaced civilians to southern Lebanon is a key tenet of the truce.

Israeli Security Minister Itamar Ben-Gvir, a right-wing member of Netanyahu's government, said on X the agreement did not ensure the return of Israelis to their homes in the country's north and that the Lebanese army did not have the ability to overcome Hezbollah.

"In order to leave Lebanon, we must have our own security belt," Ben-Gvir said.