Lebanon's army cordons off US embassy in Beirut - Reuters

"There are indications that Nasrallah was in the compound that was attacked. Those who were there have a very small chance of getting out alive," Axios said citing a senior Israeli official.

"Hezbollah should know that we will stand by their side as comrades in battle until the last moment," Iran's Parliament Speaker Mohammad Bagher Ghalibaf said in reaction to the Israeli air raid on Hezbollah's headquarters.

Israel's air strike on Beirut "changes the rules of the game," Iran's embassy in Beirut posted on X.

"Once again, the Israeli regime is committing a bloody massacre, targeting densely populated residential neighborhoods", the embassy said.

"There is no doubt that this reprehensible crime and reckless behavior represent a serious escalation that changes the rules of the game and brings upon its perpetrator appropriate punishment and discipline."

No senior leader from Hezbollah was killed Israel's air strike on Beirut, IRGC-affiliated Tasnim said citing informed sources in Lebanon.

"The operation was a failure," Tasnim quoted its sources as saying.

Reuters has also said that senior Hezbollah official Hashem Safieddine is alive, citing a Hezbollah source.

Pentagon spokesperson Sabrina Singh said that Washington received no advance warning from Israel on its attack on Beirut.

The US defence secretary Lloyd Austin was on the phone with Israeli counterpart Yoav Gallant when the air strike happened, Singh said.