Israel expanded its targets in its war with Hezbollah militants in Lebanon on Monday, killing at least 21 people in an airstrike in the north, health officials said, while millions of Israelis took shelter from projectiles fired back across the border.

So far the main focus of Israel’s military operations in Lebanon has been in the south, the Bekaa Valley in the east and the suburbs of Beirut.

The strike in the Christian-majority town of Aitou hit a house that had been rented to displaced families, the town’s mayor Joseph Trad told Reuters. In addition to the deaths, eight people were injured, the Lebanese health ministry said.

Rescue workers at the site of the strike searched through piles of rubble on Monday, where burned vehicles and trees could be seen strewn across the ground.

Israel ordered residents of 25 villages in southern Lebanon to evacuate to areas north of the Awali River, which flows some 60 km (35 miles) north of the Israeli frontier.

Prime Minister Benjamin Netanyahu, visiting a military base in central Israel where four soldiers were killed on Sunday by a Hezbollah drone strike, said Israel would continue to attack the Iran-backed movement “without mercy, everywhere in Lebanon – including Beirut”.

At the Masnaa border crossing with Syria, couple Jalal Ferhat and Amal Tefayeli and their five children were among those offloading belongings from buses, hoping to leave Lebanon.

“There are strikes in our neighbourhood and destruction, and they (Israeli forces) hit near my house,” said Ferhat, 40, from Baalbek, a Hezbollah stronghold in eastern Lebanon. “I have children, you can’t just stay where you are.”

In central Israel, residents rushed to shelters as sirens sounded. The military said three projectiles that had crossed from Lebanon had been intercepted. No injuries were reported.

The Israeli military in a statement said approximately 115 projectiles fired by Hezbollah crossed from Lebanon into Israel on Monday.

The conflict between Israel and Hezbollah resumed a year ago when the militant group began firing rockets at Israel in support of Palestinian militants Hamas at the start of the Gaza war. It has escalated sharply in recent weeks.

Israeli strikes have killed at least 2,309 people in Lebanon over the last year, the Lebanese government said in its daily update. The majority have been killed since late September when Israel expanded its military campaign. The toll does not distinguish between civilians and combatants.

Israel says its operations in Lebanon are aimed at securing the return of tens of thousands of people displaced from their homes in northern Israel.

ISRAEL AT ODDS WITH UN PEACEKEEPERS

The Israeli military said it had killed Muhammad Kamel Naim, commander of the anti-tank missile unit of Hezbollah’s elite Radwan Force, in a strike in the Nabatieh area of south Lebanon.

Hezbollah did not immediately comment.

As Israel has pushed its forces through south Lebanon in an attempt to wipe out Hezbollah and its military infrastructure, tensions have increased between Israel and the U.N. peacekeeping force UNIFIL.

The U.N. said Israeli tanks had burst into its base on Sunday.

Netanyahu on Monday rejected accusations that Israeli troops had deliberately harmed UNIFIL peacekeepers as “completely false” and repeated a call for them to withdraw from combat zones close to the border with Israel.

He said Hezbollah uses UNIFIL positions as cover for attacks that have killed Israelis, including on Sunday, when a drone attack on a military base killed four soldiers.

“Israel has every right to defend itself against Hezbollah and will continue to do so,” Netanyahu said in a statement.

He said he regretted any harm to UNIFIL personnel but added that the best way to ensure their safety was “to heed Israel’s request and to temporarily get out of harm’s way.”

The force’s spokesperson on Monday said in a video posted on X that the peacekeeping mission would stay.

“We are staying ... we are in south of Lebanon under a Security Council mandate. So it’s important to keep an international presence and to keep the UN flag in the area,” Andrea Tenenti said.

The Israeli military took foreign journalists into southern Lebanon on Sunday and showed them a Hezbollah tunnel shaft that was less than 200 metres away (650 feet) from a UNIFIL position, as well as weapon stashes that the troops found.

“We are actually standing in a military base of Hezbollah very close to the U.N.,” Brigadier General Yiftach Norkin said, pointing to the shaft’s trapdoor in an area covered by undergrowth and overlooked by a U.N. observation post.

Since announcing its ground operation near the border, the Israeli military says that it has destroyed dozens of Hezbollah tunnel shafts, rocket launchers and command posts.

UNIFIL has said previous Israeli attacks limited its monitoring abilities and U.N. sources say they fear any violations of international law in the conflict will be impossible to monitor.

Meanwhile, the Middle East remains on high alert for Israel to retaliate against Iran for an Oct. 1 barrage of missiles launched in response to Israel’s assaults on Lebanon.

The Pentagon said on Sunday it would send US troops to Israel along with an advanced US anti-missile system.

On Monday, the US embassy in Lebanon strongly encouraged its citizens to leave immediately, warning that additional flights laid on by the government to help US citizens leave since Sept. 27 would not continue indefinitely.