BEIRUT — A wave of deadly Israeli airstrikes targeted government forces in Syria and the Iran-backed group Hezbollah in Lebanon on Tuesday, escalating what Israel said were efforts to secure its northern border.

The strikes in Syria were a rare attack on forces of the new government, which is led by Islamist former rebels who toppled dictator Bashar Assad in December. Since the fall of the Assad regime, Israel has launched hundreds of airstrikes in Syria and deployed forces across a demilitarized buffer zone between the two countries.

But it has seldom attacked the government’s military and the two countries recently opened diplomatic contacts to try to lower tensions and conflict between them.

The Syrian government condemned the Israeli attack and said it was aimed at undermining the country’s stability. It said a number of its forces had been killed, as had civilians. Dozens of people have been killed this week in violence that erupted in the southern province of Sweida, triggered by a series of kidnappings involving Syria’s Druse minority and pro-government Bedouin tribal groups.

The Syrian government said it had sent forces Monday to try to calm the violence in Sweida, the Syrian Druse heartland. But those forces became embroiled in clashes with local Druse fighters, leading Israel to respond with two straight days of airstrikes on government fighters.

Both Israel and Syria have sizable Druse minorities, and in Israel, Druse serve in the national military. Israeli leaders have offered to protect Syrian Druse should they come under attack during the country’s post-Assad transition.

Sweida province is home to an array of Druse militias, many of which have resisted efforts to integrate into the new national armed forces.

The government and local Druse figures in Sweida reached an agreement Tuesday to quell the violence, although the ceasefire deal has proved shaky, with reports of continued attacks. The U.S. special envoy to Syria, Tom Barrack, said Washington was mediating to restore calm.

The clashes in Sweida were the latest flare-up of sectarian violence in Syria, where tensions linger from a nearly 14-year civil war. Footage verified by The New York Times gave a glimpse of the chaos.

One video shows houses on fire Sunday as armed men walk through al-Tireh, a village in Sweida province.

Some videos showed convoys of government-affiliated forces that appeared to be on their way to the region Monday. A graphic photo circulating on social media showed the aftermath of an ambush on those convoys.

In neighboring Lebanon, Israeli airstrikes hit the eastern Bekaa Valley, a bastion of support for Hezbollah. The attack killed 12 people.

It was the deadliest Israeli strike on Lebanon since a ceasefire was reached in November — ending the most destructive war in Lebanon in decades. The war began with Hezbollah firing rockets into Israel in solidarity with its ally, Hamas, in the Gaza Strip after Hamas led the Oct. 7, 2023, attack on Israel.

The airstrikes Tuesday targeted facilities belonging to Hezbollah’s Radwan unit, the spearhead of the group’s fighting force, according to the Israeli military. Hezbollah said the attack targeted civilian water infrastructure, calling it a “significant escalation.”

Israel’s defense minister, Israel Katz, said the attacks were “a clear message” to both Hezbollah and the Lebanese government that Israel would respond with “maximum force” to any attempt by the group to restore its military capabilities.

Meawhile, Israeli strikes overnight and into Tuesday killed more than 90 Palestinians across the Gaza Strip, including dozens of women and children, health officials said.

One strike in the northern Shati refugee camp killed a 68-year-old Hamas member of the Palestinian legislature, as well as a man and a woman and their six children who were sheltering in the same building, according to officials from Shifa Hospital, where the casualties were taken. One of the deadliest strikes hit a house in Gaza City’s Tel al-Hawa district on Monday evening and killed 19 members of the family. — The Associated Press contributed to this report.