People inspect the site of an Israeli strike in the southern suburbs of Beirut on Friday. Reuters

The Israeli military and a security source in Lebanon said Ibrahim Aqil had been killed along with other senior members of an elite Hizbollah unit in the airstrike, sharply escalating the year-long conflict between Israel and the Iran-backed group.

The Israeli military described Aqil as the acting commander of the Radwan special forces unit, and said it had killed him along with around 10 other senior commanders as they held a meeting. Aqil sat on Hizbollah’s top military council, sources in Lebanon told Reuters.

Lebanon's health ministry said Friday's strike killed 12 people and wounded 66 others, nine of whom were in critical condition. Rescue teams were searching for people under the rubble of two buildings, the country's civil defence service said.

Rescuers carry a body at the scene of a missile strike in Beirut on Friday. AP

Local broadcasters showed groups of people gathered near the site, and reported they were searching for at least 10 people who had been in the vicinity and were still missing, most of them children. Drones were still flying over Beirut's southern suburb hours after the strike.

"We are not afraid, but we want a solution. We cannot continue with the country like this," said Alain Feghali, a resident of Beirut who spoke to Reuters. "War? I don't know if it started or not, but nothing is reassuring. It is clear that the two sides will not stop."

Hizbollah did not make any official statements on the strike, and did not immediately confirm that Aqil was targeted or killed.

The UN Special Coordinator for Lebanon, Jeanine-Hennis Plasschaert, said Friday's strike in a densely populated area of Beirut's southern suburbs was part of "an extremely dangerous cycle of violence with devastating consequences. This must stop now."

The strike marked the second time in less than two months that Israel has targeted a leading Hizbollah military commander in Beirut. In July, an Israeli airstrike killed Fuad Shukr, the group's top military commander.

RUBBLE AND BURNT OUT CARS

The Israeli military reported warning sirens sounded in northern Israel following the Beirut strike. Israeli media reported heavy rocket fire in northern Israel.

Hizbollah said it had twice fired Katyusha rockets at what it described as the main intelligence headquarters in northern Israel "which is responsible for assassinations."

White House national security spokesperson John Kirby said he was not aware of any Israeli notification to the United States before the Beirut strike, adding Americans were strongly urged not to travel to Lebanon, or to leave if they are already there.

However he added that, "war is not inevitable ... and we're going to continue to do everything we can to try to prevent it."

The Iranian embassy in Lebanon said it "condemns in the strongest terms the Israeli madness that crossed all lines with targeting residential buildings in Beirut's southern suburbs."

Reuters