Watch: Moment huge explosion shakes Beirut
Video footage shows a fireball rising above Lebanon's capital overnight following another strike on the city.
Reports suggest it may have hit a petrol station, according to a map provided by the Israeli military.
The blast came after Israel's military warned people in a southern suburb to evacuate.
A BBC reporter on the ground heard six blasts and drones buzzing overhead.
The explosion follows further Israeli strikes in the city and Hezbollah has also fired dozens of rockets into northern Israel on Saturday.