Multiple explosions are heard in Beirut as Israel's military says it has attacked Hezbollah's "central headquarters".
The multiple strikes took place only about 700 to 800m from a school where displaced people from the south of Lebanon have taken refuge.
A BBC correspondent in Beirut says the blasts, in a built-up area of the capital, sounded unlike any other explosions from recent Israeli strikes.
Buildings have collapsed after the air strike in the Dahieh neighbourhood of Beirut.
One building appears to have been left leaning to one side as smoke continues to rise from some areas hit.
Rescue workers are searching through the rubble at the scene in Lebanon's capital.
There’s chaos with ambulances trying to get to the scenes and nearby roads nearby packed with people carrying rucksacks and bags, apparently trying to flee Dahieh.
Nearly 800 people have been killed in Israeli strikes in Lebanon since Monday, local officials say.
Earlier, Israeli Prime Minister Benjamin Netanyahu vowed to keep fighting Hezbollah, telling world leaders at the UN: "We are winning".
Israel says it aims to remove Hezbollah's threat, and return displaced people back to northern Israel. Hezbollah, backed by Iran, says it is acting in solidarity with Palestinians.