Lebanon was drawn into the Middle East war on March 2 when militant group Hezbollah launched rockets towards Israel to avenge the killing of Iran's supreme leader Ayatollah Ali Khamenei.

Israel responded with intense strikes on Lebanon that have killed at least 968 people and displaced over a million, according to local authorities, and by launching ground operations in the south.

AFP journalists in the Lebanese capital said three densely-populated neighbourhoods in the heart of Beirut were hit on Wednesday, killing at least 12 people and wounding 41, according to the health ministry.

In Bashoura, a whole building collapsed into a mound of rubble after being struck.

"It was at 4:00 am, we were asleep," said Sara Saleh, a 29-year-old woman displaced from Beirut's southern suburbs, long a Hezbollah bastion but where hundreds of thousands of people live.

"We fled in our pyjamas," she told AFP, after she and her family fled a school they were sheltering in nearby.

- Hezbollah TV -

Lebanon's official National News Agency (NNA) said a strike had hit an apartment in the central Zuqaq al-Blat neighbourhood, a densely-populated area close to the government's headquarters and several embassies.

Two other strikes targeted apartments in the central Basta district, another heavily populated area that Israel struck during a 2024 war with Hezbollah.

An AFP correspondent saw emergency workers at the scene in Basta where the walls of apartments on two adjacent floors appeared to have been blasted off.

Another strike later in the morning also hit Zuqaq al-Blat, where an AFP journalist saw people clearing dust and glass from cars and the streets.

Hezbollah's Al Manar TV said Mohammad Sherri, the director of its political programmes, had been killed along with his wife in one of the strikes in Zuqaq al-Blat.

Lebanese Information Minister Paul Morcos said that targeting "media professionals constitutes a flagrant violation of international law".

Hezbollah condemned what it said was Israel's "assassination" of Sherri, describing it as a "deliberate attack".

In a statement Wednesday, the Israeli army said that, on Tuesday, one of its strikes in the "area of Beirut" had killed a commander in a division linked to the Iranian Revolutionary Guards. AFP was unable to independently confirm this.

- Panic in the south -

Late Wednesday, the Israeli army renewed strikes on several towns and villages in south Lebanon, according to the NNA, while Hezbollah claimed rocket salvos on a defence company in Haifa and on Nahariya, both in northern Israel.

Israel attacked two bridges across the Litani River, which splits the south of the country.

AFP photos showed a bridge in an agricultural area north of the southern city of Tyre partially destroyed, with fires burning in the surrounding brush.

Israel said Wednesday it would target bridges crossing the Litani, "to prevent the transfer of reinforcements and weapons" to the frontlines, essentially cutting off a large part of the south from the rest of the country.

In a statement issued after the twin bridge attacks, the Israeli defence minister said: "This is a direct action against Hezbollah's use of Lebanon's state infrastructure... and also a clear message to the Lebanese government: the State of Israel will not allow such a reality."

Israel struck at least five gas stations belonging to the Al-Amana fuel company, which it said finances Hezbollah.

This came as Hezbollah announced it had repelled an attempt by "Israeli enemy soldiers to advance" in Khiam, a town about six kilometres (four miles) from the border that has witnessed fierce clashes in recent days.

Late Tuesday, the Israeli military had issued an evacuation order for most of the city of Tyre as well as swathes of surrounding areas, sending people fleeing northwards, an AFP correspondent said.

In a statement on Wednesday the UN peacekeeping force in Lebanon (UNIFIL) said "last night's violent escalation marks a further worrying deterioration".

"Heavy exchanges of fire, intensified air and ground activity, and increased presence of Israeli forces inside Lebanese territory are deeply concerning developments," it added.