Lebanese armed group Hezbollah confirmed its media relations chief Mohammad Afif was killed by an Israeli strike on a building in central Beirut on Sunday.
Israel's military, which earlier declined to comment, issued a statement late on Sunday reporting it had "eliminated" Afif. The Lebanese health ministry said the strike had killed one and injured three.
A second, separate strike later on Sunday hit Mar Elias street, another central area rarely targeted by Israeli bombs, Hezbollah's Al-Manar TV reported. The Lebanese health ministry said that strike killed at least two people and wounded 22.
Hezbollah and Israel have been trading fire for more than a year, since the group began launching rockets at Israeli military targets on October 8, 2023.
In late September, Israel expanded its military campaign in Lebanon, heavily bombing the south and east and the southern suburbs of Beirut alongside ground incursions on the border.
Israel's campaign in Lebanon has in the last year killed 3,841 people and wounded nearly 15,000 others, the Lebanese health ministry said on Sunday.
On Thursday, two Israeli airstrikes killed 16 paramedics at Civil Defense centres in Baalbek-Hermel and Nabatiyeh.
In the Gaza Strip, Israel has killed more than 43,000 people, most of them civilians, and displaced 90 per cent of the population.
In addition to targeting Hezbollah, the escalation has killed several soldiers of the Lebanese military, including two who died on Sunday when Israel attacked an army post in the southern town of Al-Mari, the Lebanese army said on X.
Two other soldiers were wounded, it said.
The strike in Beirut targeting the Hezbollah official hit the Ras al-Nabaa neighbourhood, where many people displaced from the southern suburbs by Israeli bombardment have sought refuge.
The Lebanese security sources said a building housing offices of the Ba'ath Party had been hit, and the head of the party in Lebanon, Ali Hijazi, told the Lebanese broadcaster Al-Jadeed that Afif had been in the building.
Ambulances could be heard rushing to the scene, and guns were fired to prevent crowds approaching.
The Lebanese broadcaster showed video of a building whose upper floors had collapsed and civil defence workers at the scene.
Afif was a long-time media adviser to Hezbollah secretary-general Hassan Nasrallah, who was killed in an Israeli air attack on the southern suburbs of Beirut on September 27.
He managed Hezbollah's Al-Manar television station for several years before taking over the group's media office.
Afif hosted several press conferences for journalists among rubble in Beirut's southern suburbs. In his most recent comments to reporters on Nov. 11, he said Israeli troops had been unable to hold any territory in Lebanon, and that Hezbollah had enough weapons and supplies to fight a long war.