The deadly incident occurred in the Tariq al-Jadida neighborhood of the capital on Friday evening, when a fuel tank went off and caused a large fire to break out in some nearby buildings, spreading panic across the city.
“The number of victims increased to four,” the Lebanese Red Cross said tweeted, updating the toll from two dead.
According to the Beirut-based Al-Jadeed television, nearly 30 people, including children, were hurt in the blaze. It also ran footage showing flames leaping into the night sky.
The immediate cause of the fire was not known.
A number of fires have been broken out in Beirut since a cataclysmic explosion killed 203 people on August 4, when almost 6,500 others were injured, as the country was already grappling with an economic crisis.
The gigantic blast occurred when 2,750 tons of ammonium nitrate, a highly explosive fertilizer, went up in smoke at Beirut port, leaving up to 300,000 people homeless. It also inflicted major damage to downtown areas of the city.