Israel has carried out a series of airstrikes in the Nabatieh district, south Lebanon, in response to Hezbollah rocket fire near a watchtower, in the deadliest attacks since a ceasefire came into effect last week.

The Israeli PM, Benjamin Netanyahu, promised there would be a strong response to Hezbollah’s attack, and the Israeli military later said it had “struck Hezbollah terrorists, dozens of launchers, and terrorist infrastructure throughout Lebanon”.

Lebanon’s health ministry said at least nine people had been killed in Israeli strikes on the two southern towns of Haris and Talousa. The Israeli bombing constituted the most significant attacks since the ceasefire was established on Wednesday.

The Israeli military had previously carried out several strikes over the past week, but at a lower intensity. Israeli media reported on Sunday that France, which is supposed to supervise the implementation of the deal, had accused Israel of violating the ceasefire agreement 52 times since its establishment.

Hezbollah had launched two rockets near a watchtower in the occupied Shebaa farms earlier on Monday night. They landed in an open area and caused no injuries. In a statement, the group said the attack on the watchtowers was an “initial warning defensive response” against “repeated violations” by Israel of the ceasefire agreement.

The resumption of tit-for-tat strikes in south Lebanon and north Israel has caused concern that fully-fledged fighting between Hezbollah and Israel could resume just five days after a ceasefire was announced.

Residents of Lebanon braced themselves for Israel’s response to Hezbollah’s attack on Monday night, with a witness saying that people started leaving Dahiyeh, the southern suburbs of Beirut where Hezbollah enjoys strong support, shortly after Netanyahu vowed to retaliate.

“We are tired, we can’t handle any more of this. People barely just got back to their homes,” said Ali, a resident of Beirut from Tyre, south Lebanon.

Fighting has taken a heavy toll in Lebanon, with almost 4,000 people killed by Israeli strikes, more than 1 million people displaced and £6.7bn in damages over the last 13 months. Residents of south Lebanon had just begun to return to their homes this week and begin repairs. In north Israel, more than 60,000 people remain displaced by Hezbollah rockets.

The ceasefire mandates that Israeli troops leave south Lebanon and Hezbollah’s fighters vacate the area south of the Litani River, about 18 miles north of the Israel-Lebanon border, within 60 days. The deal ended 13 months of fighting that began after Hezbollah launched rockets at Israel on 8 October 2023 “in solidarity” with Hamas’s attack a day prior.

A key point of contention in the ceasefire has revolved around Israel’s right to unilaterally enforce what it deems to be violations of the truce. Israel has sought assurances from the US that it could take action against Hezbollah on its own if the Lebanese army fails to stop Hezbollah from acting in south Lebanon.

Israeli officials have stressed that it will maintain the right to carry out attacks and reopen the front in Lebanon if it feels the ceasefire deal is not being respected.

During a tour in south Lebanon on Monday morning, the head of Israel’s military Lt Gen Herzi Halevi said: “We will attack with great force in the face of Hezbollah’s dangerous violations, this is what we will continue to do. We have plans and targets that are ready to be implemented at any moment.”

Hezbollah has said that Israel does not have the right to carry out attacks in Lebanon or fly its aircraft in Lebanese airspace, saying this would be an encroachment of Lebanese sovereignty. The Hezbollah MP, Hassan Fadlallah, said on Wednesday that the group is ready to respond if Israel violates the truce, saying the ceasefire agreement recognises “the right of the two parties to self-defence”.

Analysts have said that Hezbollah, weakened from more than a year of fighting, does not want to reignite a war with Israel but must play a balancing act by not appearing too docile in the face of continuing Israeli strikes.

Western diplomats have reportedly cautioned Israel to be less aggressive in its attacks on Lebanon and urged it to allow the monitoring mechanism, which is meant to supervise the ceasefire, to begin its work. US Maj Gen Jasper Jeffers arrived in Beirut on 27 November to co-chair the ceasefire committee alongside US envoy Amos Hochstein.

During a briefing with reporters on Monday, state department spokesperson Matthew Miller said the ceasefire had not broken down and that the US-led enforcement mechanism would address violations.

“If we do see violations of the ceasefire, we’ll go to the parties and tell them to knock it off,” Miller said.