Australians have been warned to get out of Lebanon and Iran amid fears of full-scale war triggered by the killing of Hamas and Hezbollah leaders, and Israel’s vow to “exact a heavy price” for any retaliations.

Prime Minister Benjamin Netanyahu on Thursday (AEST) said Israel had delivered crushing blows to Iran’s proxies over the past few days, including Hamas and Hezbollah.

He did not mention Haniyeh’s killing, which has drawn threats of revenge on Israel and fuelled further concern that the conflict in Gaza was turning into a wider Middle East war.

“Citizens of Israel, challenging days lie ahead. Since the strike in Beirut there are threats sounding from all directions,” said Netanyahu in a televised statement.

“We are prepared for any scenario and we will stand united and determined against any threat. Israel will exact a heavy price for any aggression against us from any arena.

Australia’s Department of Foreign Affairs (DFAT) has advised Australians not to travel to Lebanon and Iran due to the “volatile security situation and the risk of the security situation deteriorating further”.

“Australians in Lebanon should leave immediately while commercial flights remain available,” says a SmartTraveller warning.

“The security situation could deteriorate rapidly throughout Lebanon with little or no notice.

“Some airlines have postponed or cancelled some flights. Further flight cancellations and disruptions could occur with little or no notice.”

On Iran, DFAT states: “Regional tensions are high, and the security environment could deteriorate with little or no notice.”

Israel’s military announced late on Wednesday (AEDT) it had killed Fuad Shukr, whom it named as Hezbollah’s most senior commander and whom it blamed for an attack at the weekend that left a dozen youngsters dead in the Israeli-occupied Golan Heights.

Shukr was an adviser to Hezbollah leader Sayyed Hassan Nasrallah, according to Hezbollah sources and to Israeli officials.

Hezbollah confirmed his death, hours after the Palestinian armed group Hamas announced its leader, Haniyeh, had been assassinated in the Iranian capital Tehran.

Although the Tehran attack was widely assumed to have been carried out by Israel, Netanyahu’s government made no claim of responsibility and said it would make no comment on Haniyeh’s killing.

Haniyeh was killed by a missile that hit him “directly” in a state guesthouse where he was staying, Khalil al-Hayya, a senior Hamas official, told a news conference in Tehran, quoting witnesses who were with Haniyeh.

“Now we are waiting for the full investigation from the (Iranian) brothers,” al-Hayya said.

Haniyeh, normally based in Qatar, had been the face of Hamas’ international diplomacy as the war set off by the Hamas-led attack on Israel on October 7 has raged in Gaza.

He had been taking part in internationally-brokered indirect talks on reaching a ceasefire in the Palestinian enclave.

Two Lebanese security sources said on Wednesday that the body of Shukr had been found in the rubble of a building hit by an Israeli air strike in Beirut’s southern suburbs.

-with AAP