Video shows a fireball rising over the Lebanese capital overnight after another attack on the city.
Reports suggest it may have hit a gas station, according to maps provided by the Israeli military.
The explosion occurred after the Israeli army warned people in the southern suburbs to evacuate.
A BBC reporter on the ground heard six explosions and drones buzzing overhead.
The blast followed further Israeli attacks on the city and Hezbollah also fired dozens of rockets into northern Israel on Saturday.
