A Lebanese security source said Hezbollah spokesman Mohammed Afif was killed in an Israeli strike Sunday in central Beirut that hit the Lebanese branch of the Syrian Baath party.
"The strike on Ras al-Nabaa killed Hezbollah media relations official Mohammed Afif," the security source said, requesting anonymity as they were not authorised to brief the media.
Ali Hijazi, secretary-general of the Lebanese branch of the Baath party, "confirmed the death of Hezbollah media official" Afif, the official National News Agency reported.
The Israeli army declined to comment, but Afif is the latest in a long line of Hezbollah officials killed since Israel on September 23 began heavily bombarding Hezbollah strongholds after almost a year of cross-border exchanges with the Iran-backed group over the Gaza war.
Lebanon's health ministry said the strike killed one person and wounded three others, adding that the toll was provisional and that work was ongoing to remove rubble from the site of the strike.
Afif was part of the inner circle of longtime Hezbollah chief Hassan Nasrallah, who was killed in an Israeli strike in September.
For years, Afif had been responsible for Hezbollah's media relations, providing information to local and foreign journalists, often under the cover of anonymity.
The NNA said the strike by "enemy aircraft" caused "great destruction", reporting an unspecified number of people "trapped under the rubble" in Ras al-Nabaa, an area near the French embassy and a university.
It said "one of the residents of a neighbouring building had received a warning call urging evacuation but it was not taken seriously".
Afif joined Hezbollah at a young age and first came to prominence as information director for Hezbollah's television channel Al-Manar when the group and Israel went to war in 2006.
After Nasrallah's assassination, Afif had held several press conferences in Beirut's southern suburbs, including one last month in which he announced Hezbollah had launched a drone targeting the residence of Israeli Prime Minister Benjamin Netanyahu.
That press conference was cut short when the Israeli army warned it would strike a building nearby.
"Bombardments have not scared us, so how would threats?" Afif said defiantly as journalists hurriedly collected their microphones from the table.
Hezbollah officials killed in previous Israeli strikes include not only Nasrallah but also Hashem Safieddine, tipped as the former chief's successor.