More than a dozen explosions rocked Beirut on Monday, witnesses said, in the most intensive strikes on the southern suburbs since a war between Israel and Hezbollah in 2024.
Lebanese security sources said airstrikes hit several areas of the southern suburbs, known as Dahiyeh.
The Israeli military said it had begun striking Hezbollah targets across Lebanon and held Hezbollah responsible.
"Hezbollah opened a campaign against Israel overnight, and is fully responsible for any escalation," Israeli Chief of the General Staff, Eyal Zamir, said in a statement.
The projectiles launched by Hezbollah were the first since the start of US and Israeli strikes on Iran.
Israel also carried out airstrikes in southern Lebanon and the Bekaa Valley in eastern Lebanon, the Lebanese security sources said.
The Shi'ite Muslim group, long one of Tehran's principal allies in the Middle East, said it launched the attack against Israel in response to Israel killing Khamenei and continuous Israeli violations against Lebanon.
"The resistance leadership has always emphasised that the continuation of Israeli attacks and the assassination of our leaders, youth, and people gives us the right to defend ourselves and respond at the appropriate time and place," Hezbollah said in a statement.
"The IDF (Israel Defense Forces) will operate against Hezbollah's decision to join the campaign, and will not enable the organisation to constitute a threat to the State of Israel," the Israeli military said.
Israel and Lebanon agreed to a US-brokered ceasefire in 2024, ending more than a year of fighting between Israel and Lebanese militant group Hezbollah that had culminated in Israeli strikes that severely weakened the Iran-backed group. Since then, the sides have traded accusations over violations.
Lebanon's presidency said on Saturday it had been told by the US ambassador that Israel would not escalate against Lebanon as long as there are no hostile acts from the Lebanese side.
with AP
