The Israel Defense Forces struck a building in southern Beirut on Tuesday evening, targeting a senior Hezbollah commander Israel said was responsible for Saturday’s deadly rocket attack on Majdal Shams.

A loud blast was heard and a plume of smoke could be seen rising above the southern suburbs — a stronghold of the Iran-backed Lebanese terror group — at around 7:40 p.m., a Reuters witness said. According to Sky News Arabia, at least one woman was killed and others were injured in the strike. AFP reported that two people were killed, citing a source close to Hezbollah.

The Israeli military took credit for the strike, saying that the commander in question was also responsible for other deadly attacks on Israel. It was not immediately clear if the targeted assassination was successful, with conflicting reports citing Israeli and Lebanese security officials. Shortly after the strike, Defense Minister Yoav Gallant tweeted in English: “Hezbollah crossed the red line.”

The targeted commander was reported by multiple media outlets to be Fuad Shukr, also known as Hajj Mohsin, a senior adviser to the terror group’s leader, Hassan Nasrallah.

Shukr was named by the IDF several years ago as a commander of Hezbollah’s precision missile project. He is also wanted by the United States for his role in the 1983 bombing of a US Marines barracks in Beirut, with a $5 million bounty placed on his head by Washington.

According to the US State Department’s Rewards for Justice program, in addition to advising Nasrallah, Shukr sits on the Jihad Council, Hezbollah’s top military body.

Shukr played a “central role” in the 1983 bombing of US Marine Corps barracks that left 241 US marines dead, according to the State Department. The State Department reported that during the Syrian civil war he “aided [Hezbollah] fighters and pro-Syrian regime troops” as they battled anti-Assad forces.

Lebanon’s state-run national news agency said the Israeli strike targeted the area around Hezbollah’s Shura Council in the Haret Hreik neighborhood of Beirut.

It was the first Israeli attack on the Lebanese capital since a January strike that killed Hamas’s deputy leader abroad Saleh al-Arouri.

The strike came after days of Israeli officials threatening a harsh response to the Hezbollah rocket attack that killed 12 children playing on a soccer field and playground in Majdal Shams, a Druze town in the Golan Heights. The IDF said Tuesday evening that there were no immediate changes to the Home Front Command guidelines for Israeli civilians, despite fears of a possible Hezbollah counterattack.

The Israeli airstrike was precipitated by a flurry of diplomatic activity with Western nations seeking to avoid a larger escalation and urging both Israeli and Lebanese officials to practice restraint. A number of airlines canceled flights to Beirut over the past few days, and Lufthansa canceled several flights to Tel Aviv.

Shortly after the strike, US State Department deputy spokesman Vedant Patel told a briefing that “we’re continuing to work toward a diplomatic resolution that would allow Israeli and Lebanese civilians to return to their homes and live in peace and security. We certainly want to avoid any kind of escalation.”

Patel reiterated that US support for Israel remained “ironclad” and that “Israel has every right to defend itself” and “certainly faces threats like no other country does in that region of the world.”

The Russian foreign ministry called the Israeli strike on Beirut “a flagrant violation of international law,” according to the Russian state-run TASS news agency.

According to the Kan public broadcaster, the security cabinet was not updated ahead of the strike in Beirut. The outlet also reported that the US is expected to approve of the strike, especially given the fact that Shukr was wanted for the killing of 241 US servicemen. Channel 12 news reported that ministers were ordered not to publicly comment on the strike.

The heads of UNIFIL — the United Nations peacekeeping force in Lebanon — and UN Special Coordinator for Lebanon Jeanine Hannis-Plasschaert were speaking to both Lebanon and Israel in an attempt to prevent the outbreak of war, UN Secretary-General spokesman Stéphane Dujarric said.

Earlier Tuesday, Hezbollah fired a volley of 10 rockets toward the Upper Galilee, killing an Israeli civilian in Kibbutz HaGoshrim. The victim was later named as Nir Popko, 28, from the kibbutz.

The IDF said that most of the rockets fired by Hezbollah were intercepted by the Iron Dome missile defense system. Hezbollah claimed responsibility for the attack, saying it had launched dozens of rockets at a nearby military base. The military said it was shelling the launch site with artillery.

Since October 8, Hezbollah-led forces have attacked Israeli communities and military posts along the border on a near-daily basis, with the group saying it is doing so to support Gaza amid the war there.

So far, the skirmishes have resulted in 25 civilian deaths on the Israeli side — including in Tuesday’s attack —  as well as the deaths of 18 IDF soldiers and reservists. There have also been several attacks from Syria, without any injuries.

Hezbollah has named 384 members who have been killed by Israel during the ongoing skirmishes, mostly in Lebanon but some also in Syria. In Lebanon, another 68 operatives from other terror groups, a Lebanese soldier, and dozens of civilians have been killed.