The building, in the Bachoura area of the capital, is close to Lebanon's parliament and the United Nations headquarters.

Officials said two people died immediately after the strike, while four others died later.

It is the second time this week Israel has struck the city.

Middle East latest: Eight IDF soldiers killed in Lebanon fighting

On Wednesday, the Israeli military said seven soldiers were killed in two Hezbollah attacks in southern Lebanon.

The deaths followed an earlier announcement of the first Israeli combat death in Lebanon since the start of the incursion - a 22-year-old captain.

Another seven troops were wounded.

The Israeli military has warned people to evacuate about 50 villages and towns across southern Lebanon as its activities continue.

It comes after Iran launched dozens of missiles into Israel on Tuesday night.

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Most of the missiles were intercepted, Israel said, with US help, but Israeli Prime Minister Benjamin Netanyahu vowed to respond, labelling the Iranian strikes a "major mistake".

However US President Joe Biden gave an emphatic "no!" when asked by reporters if he would support an Israeli strike against Iran's nuclear facilities.

Meanwhile, more British nationals are expected to be airlifted out of Lebanon.

A plane organised by the UK government carrying Britons from Lebanon landed in Birmingham on Wednesday evening with another flight set to depart Beirut on Thursday afternoon.

The flight was chartered to help meet any additional demand for British nationals and their dependants wanting to leave Lebanon.

The Foreign Office has said any further flights in the coming days will depend on demand and the security situation on the ground.