Fears of a wider regional war in the Middle East grew further on Sunday, a day after a rocket attack on occupied Golan Heights prompted Israeli response in southern Lebanon.

Israel vowed retaliation after the attack, allegedly carried out by Hezbollah, killed 12 youths in the Israeli-controlled Syrian territory.

The strike has raised fears of a broader regional war between Israel and Hezbollah, which denied a role in the attack.

Overnight, the Israeli military said it struck a number of targets inside Lebanon, though the intensity of the strikes was similar to months of cross-border fighting between Israel and Hezbollah.

Saturday’s attack comes at a sensitive time, as Israel and Hamas are negotiating a cease-fire proposal to end the nearly 10-month war in Gaza and free the roughly 110 hostages who remain captive there.

The rocket slammed into a football pitch where dozens of youths were playing in the Druze town of Majdal Shams, located about 12 kilometers (7 miles) south of Lebanon.

"I feel darkness inside and out. Nothing like this happened here," Anan Abu Saleh, a Majdal Shams resident, said from the field on Saturday night. "There’s no way to explain this. I saw children, I don’t want to say what I saw, but its horrible, really horrible. We need more security."

On Sunday morning, many of the bodies were brought to a community center in Majdal Shams, where family members wailed over the coffins.

At midday, the coffins, draped in white cloth and bearing photos of the victims, were brought to the cemetery, passed through a crowd of thousands and lined up for burial. One 11-year-old child is still missing, residents told Israeli media.

The Druze are a religious sect that began as an offshoot of Shiite Islam. There are Druze communities in Israel, Syria and Lebanon. There are about 140,000 Druze in Israel, 25,000 of whom live in four towns in the Israeli-controlled Golan Heights, according to Yusri Hazran of the Hebrew University, who is Druze and researches minorities in the Middle East.

The Druze community is considered among Israel’s most loyal citizens. Many Druze serve in the Israeli military, although those living in the Golan Heights have a more fraught relationship with the authorities.

Israel captured the Golan, a strategic plateau overlooking northern Israel, from Syria in the 1967 Mideast war and annexed it in 1981. Much of the international community considers the area to be occupied territory.

While Druze leaders in the Golan still profess allegiance to Syria, relations with Israel are normally good. The Druze towns in the Golan are a popular vacation destination for Israelis and are filled with hotels and restaurants and most Druze residents speak fluent Hebrew.

The attacks on the Israel-Lebanon border have simmered just below the threshold of an all-out war since Tel Aviv launched its genocidal war on Gaza last October. However, the deadly toll of the attack and the young age of the victims could push Israel to respond more severely.

The Iranian-backed Hezbollah began firing rockets at Israel the day after Hamas' incursion on Oct. 7 and Israel has responded by targeting what it says is Hezbollah military infrastructure with airstrikes and drones.

'Pay heavy price'

Most of the attacks have been confined to the area on either side of the border, though Israel has also assassinated Hezbollah and Hamas leadership farther north in Lebanon. Tens of thousands of people on both sides of the border have evacuated the area.

Since early October, Israeli airstrikes in Lebanon have killed more than 500 people, including many civilians. On the Israeli side, 22 soldiers and 24 civilians have been killed.

Israeli Prime Minister Benjamin Netanyahu, who was in America at the time of the strike, warned that Hezbollah "will pay a heavy price for this attack, one that it has not paid so far."

The Israeli military’s Chief of Staff Lt. Gen. Herzi Halevi met with leaders of Majdal Shams on Saturday night, and said Israel was preparing for "the next stage of fighting" in the north. "We know how to strike even very far from the state of Israel," he said.

In a rare move, Hezbollah denied it was responsible for the attack, but Halevi claimed the rocket was a Falaq rocket with a 53-kilogram warhead that belonged to Hezbollah.

U.S. intelligence officials accused Hezbollah of the attack but it was not clear if the group intended the target or misfired, according to a person familiar with the matter who was not authorized to comment publicly.

Lebanon’s government, in a statement that didn’t mention Majdal Shams, urged an "immediate cessation of hostilities on all fronts" and condemned all attacks on civilians.

Iran on Sunday warned Israel that a strong reaction to the Golan Heights strike will lead to "unprecedented consequences."

"Any unwise action by the Zionist regime is a ground-paving for expansion of instability, insecurity and war in the region," said Nasser Kanaani, the spokesperson for the Iranian Foreign Ministry.

Iran and Israel's yearslong shadow war burst into the open in April, when Iran launched 300 missiles and drones at Israel, most of which were intercepted, in response to the killing of an Iranian general.

An Egyptian official said the attack in the Israeli-controlled Golan Heights could give urgency to the negotiations to reach a cease-fire deal in Gaza, which would be reflected on the Israeli-Hezbollah front.

He said mediators will use such an attack to press for a cease-fire in Gaza to avoid an all-out war in the region.

"Both fronts are connected," he said. "A cease-fire in Gaza will lead to a cease-fire with Hezbollah."

The official spoke on condition of anonymity because he wasn’t authorized to discuss the sensitive talks with the media.

Officials from the United States, Egypt and Qatar are meeting Sunday with Israeli officials in Rome in the latest push for a cease-fire deal in Gaza.