"The strike on Ras al-Nabaa killed Hezbollah media relations official Mohammed Afif," a Lebanese security source told AFP.

Media reports said it targeted a building where the offices of the Lebanese branch of the Syrian Baath party are located.

Ali Hijazi, secretary-general of the Lebanese branch, "confirmed the death of Hezbollah media official," Afif, Lebanon's National News Agency, reported.

Earlier, Lebanon's health ministry said at least one person was killed and three others wounded Sunday in an Israeli strike on Ras al-Nabaa, but did not identify who was killed.

The central Beirut district has been sheltering people displaced by Israel’s carpet bombing of Beirut’s southern suburbs that escalated in September.

Ambulances could be heard rushing to the scene, and bursts of gunfire rang out to prevent crowds of people from approaching the location.

The "Israeli enemy strike on Ras Al-Nabaa led to a preliminary toll of one dead and three others wounded," a ministry statement said, adding that work was ongoing to remove rubble from the site of the strike.

Afif for years had been responsible for Hezbollah's media relations, and provided information to local and foreign journalists under the cover of anonymity.

Lebanon's National News Agency 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.

At least seven Israeli strikes hit separate locations in the area, it added, some sending thick clouds of white smoke over the targets, according to the AFPTV images.

The raids followed two rounds of Israeli army evacuation orders for sites in the Hadath, Burj al-Barajneh, Chiyah and Haret Hreik areas.

The NNA said "enemy aircraft" launched a heavy strike near St. Georges Hospital in Hadath, while another hit a "residential complex" in Haret Hreik.

Another raid "completely destroyed a 12-storey residential building near the Mar Mikhail church" in Chiyah, it said.

Since September 23, Israel has launched an aggressive bombing campaign on Lebanon, later invading the country following almost a year of cross-border exchanges between its military and Lebanon's Hezbollah.

Earlier, the Israeli military said about 20 projectiles were identified crossing from Lebanon into Israel on Sunday, with the country's air defence system intercepting some of them.

Guarding the Lebanon border, Hezbollah said it had engaged in overnight fighting with invading Israeli forces near Chamaa, about five kilometres (three miles) from the border with Israel.