Israeli military says strike in Beirut is retaliation for Golan Heights ...

An Israeli airstrike targeted a senior Hezbollah commander in Beirut's southern suburbs late on Tuesday, in what the Israeli military said was retaliation for a cross-border rocket attack three days before that killed 12 children.

A loud blast was heard and a plume of smoke could be seen rising above the southern suburbs of the Lebanese capital — a stronghold of the Iran-backed armed group Hezbollah — at about 7:40 p.m. local time, a Reuters witness said.

The Israeli strike had targeted but failed to kill Hezbollah's operations chief, two security sources told Reuters.

Lebanon's state-run national news agency said an Israeli airstrike had targeted the area around Hezbollah's Shura Council, in the capital's Haret Hreik neighbourhood of the capital.

The strike hit an apartment building next to a hospital, collapsing half of the targeted building. The hospital sustained minor damage, while the surrounding streets were littered with debris and broken glass. Paramedics could be seen carrying several injured people out of the damaged buildings.

A forklift was in the middle of the street, reaching to the top floors of the destroyed building, while utility crews removed fallen power lines. Crowds gathered to inspect the damage and check on their families. Some of them chanted in support of Hezbollah.

A resident of the suburb whose home is about 200 metres away said that dust from the explosion "covered everything" and that the glass in his son's apartment was broken.

"Then people went down on the streets," he said. "Everyone has family. They went to check on them. It was a lot of destruction." He spoke on condition of anonymity out of concerns about his security.

WATCH | Mayhem in Beirut:

Israel's military is confirming it carried out a strike targeting one of Hezbollah's commanders they say was responsible for a rocket blast in the Israeli-occupied Golan Heights this weekend that killed 12 children. While Hezbollah has denied responsibility, reporter Irris Makler breaks down what's at stake.Hezbollah denies involvement in Golan Heights attack

Lebanese Foreign Affairs Minister Abdallah Bou Habib said his government condemned the Israeli strike and planned to file a complaint with the United Nations. He told Reuters he hoped any response by Lebanese armed group Hezbollah, whose heartland is in those southern suburbs, would not trigger an escalation.

Beirut has been on edge for days ahead of an anticipated Israeli attack in reprisal for the rocket strike on the Israeli-occupied Golan Heights on Saturday that killed the 12 children in a football field in a Druze village.

Hezbollah has denied involvement in that attack.

In a statement, the Israeli military said it had conducted "a targeted strike in Beirut on the commander responsible for the murder of the children in Majdal Shams and the killing of numerous additional Israeli civilians." Details would follow.

Earlier on Tuesday, more rocket fire from south Lebanon killed a civilian in a kibbutz in northern Israel, medics said.

Shortly before the explosion in south Beirut, the Israeli military said 15 projectiles had been fired across the Lebanese border within the past few hours, with impacts in parts of the Upper Galilee region. No injuries were reported.

Israel's air force had just hit a Hezbollah observation post and "terror infrastructure" in south Lebanon, it said.

WATCH | Lebanon braces for retaliatory attack:

After a rocket strike on Saturday at a soccer field killed 12 children and teens, Israeli Prime Minister Benjamin Netanyahu warned that Hezbollah 'will pay a heavy price for this attack, one that it has not paid so far.'Concerns about escalation

As diplomats sought to contain the fallout, U.S. Defence Secretary Lloyd Austin said he did not believe a fight was inevitable between Hezbollah and Israel, although he remained concerned about the potential for escalation.

Hezbollah and Israel, which last fought each other in a major war in 2006, have been trading fire since the eruption of the Gaza war in October, after Hezbollah began firing at Israeli targets in what it says is solidarity with Palestinians.

The hostilities have mostly been limited to the frontier region, and both sides have previously indicated they do not seek a wider confrontation — even as the conflict has prompted worry about the risk of a slide toward war.

In the latest exchanges of fire on Tuesday, the Israeli military said 10 rockets had been fired from Lebanon and one hit Kibbutz Hagoshrim, causing one casualty. Israel's ambulance service said the 30-year-old male died of shrapnel wounds.

Israel said it hit some 10 Hezbollah targets in south Lebanon overnight and killed one Hezbollah fighter. Hezbollah confirmed one of its fighters was killed.