An Israeli drone strike on Hamas’ offices in Lebanon killed four of the terror group’s members including Saleh al-Arouri, its deputy political leader, Hamas and Hezbollah officials claimed tonight as they vowed to retaliate.

Israel’s Prime Minister Benjamin Netanyahu had threatened to kill al-Arouri, who headed the organisation in the West Bank and helped to found the group’s armed wing, even before Hamas launched its bloody October 7 attack.

Israeli officials tonight vowed that all Hamas leaders ‘are doomed to death’, but declined to comment on whether their forces had carried out the Beirut attack.

Hamas condemned the killing as a ‘cowardly assassination’ by Israel and declared that such attacks ‘will not succeed in breaking the will and steadfastness of our people, or undermining the continuation of their valiant resistance’.

Hezbollah leader Sayyed Hassan Nasrallah earlier pledged to retaliate against any Israeli targeting of Palestinian officials in Lebanon. As the most senior Hamas figure killed since the war erupted almost 90 days ago, al-Arouri’s death could provoke major retaliation, with Israel anticipating that its enemies could launch revenge rocket attacks.

Lebanon’s National News Agency (NNA) reported on Tuesday that the raid had been carried out by an Israeli drone, killing four and injuring a number of others. The building said to house Hamas’ offices is in Dahiyeh, an area in Beirut’s southern suburbs which is also a stronghold of the Iran-backed Hezbollah.

The explosion shook Musharafieh, one of the Lebanese capital’s southern suburbs, which are a stronghold of the militant Hezbollah group, an ally of Hamas. It caused a fire in Hadi Nasrallah Street south of Beirut.

Video footage of the aftermath of the attack on Beirut, which took place at 5.45pm local time (3.45pm UK time) and reportedly targeted both the building and a nearby car, shows a large fire burning on a nearby street, which is covered in dust and rubble.

Sirens can be heard wailing, and several cars can be seen with their windows broken in. Parents were seen holding their children tightly as they rushed to evacuate the affected area.

Iran’s Foreign Minister joing Hamas and Hezbollah in condemning what they described as the violation of Lebanon’s sovereignty.

Minister Nasser Kanaani said in a chilling response to the attack that the ‘martyr’s blood will undoubtedly ignite another surge in the veins of resistance and motivation to fight’ against Israel.

Israel’s Rear Admiral Daniel Hagari, speaking to the media on Tuesday, made no direct mention of the death of the Hamas official.

‘We are focused and remain focused on fighting against Hamas,’ he said. But he added: ‘We are on high readiness for any scenario.’

Netanyahu said at a press conference in November that he had ‘instructed the Mossad to act against the heads of Hamas wherever they are,’ following the terror group’s incursion on October 7 that left 1,200 people, mostly civilians, dead.

al-Arouri, 57, was the deputy head of Hamas’ political bureau, and was considered the de facto leader of the organisation’s military wing.

He is believed to have planned and helped execute the 2014 kidnapping and subsequent murder of three Israeli teenagers, Gil-ad Shaar, Eyal Yifrach and Naftali Fraenkel, along with several other attacks.

The political leader has been behind bars in Israel on several occasions, and was released in March 2010 as part of efforts to obtain a broader prisoner swap in exchange for Gilad Shalit, an IDF corporal kidnapped by Hamas in 2006.

al-Arouri was later involved in a deal that saw more than 1,000 Palestinian prisoners freed in exchange for the corporal.

In 2015, the US Department of the Treasury designated Arouri as a Specially Designated Global Terrorist offering five million dollars (PS4 million) for information about him.

Asked about assassination threats against him in an interview with Beirut-based Al-Mayadeen in August, Arouri said: ‘It is not strange for us for the commanders and cadres of the movement to be martyred.

‘I never expected to reach this age, so I am living on borrowed time.’

In the same interview, he threatened that in case of a comprehensive war, ‘Israel will suffer a defeat unprecedented in history’.

Lebanese media reported that, according to sources in Islamic Jihad, the secretary general of Hamas, Ziyad al-Nakhala, was not harmed in Tuesday’s explosion in Beirut.

The explosion in Beirut came following more than two months of heavy exchanges of fire between Israeli troops and members of Hezbollah along Lebanon’s southern border.

Since the fighting began the day after Black Saturday, conflict has been concentrated a few miles from the border but on several occasions Israel’s air force hit Hezbollah targets deeper in Lebanon.

Earlier in the day, Hezbollah said its fighters carried out several attacks along the Lebanon-Israel border targeting Israeli military posts.

Clashes on the Israel-Lebanon border have already displaced tens of thousands of people, despite previous claims from Israel that it did not want to wage war with its neighbour.

But just last month, senior member of Benjamin Netanyahu’s war cabinet Benny Gantz said that the situation on Israel’s border with Lebanon ‘must change’, hinting at an escalation with Hezbollah.

In November, Israel’s minister for defence Yoav Gallant said, referring to Hezbollah’s secretary general, Hassan Nasrallah: ‘If you hear that we have attacked Beirut, you will understand that Nasrallah has crossed that line.’