It was not immediately clear what caused the blaze just over a month after the August 4 blast which killed more than 190 people.
The August 4 blast sparked widespread outrage after it emerged authorities had been aware for years of the presence of the huge stockpile of ammonium nitrate that blew up, and the scandal forced the government to resign.
A huge fire raged in Beirut port on Thursday, sparking alarm among Lebanese still reeling from the devastating dockside explosion that disfigured the capital last month.
It was not immediately clear what caused the blaze just over a month after the August 4 blast which killed more than 190 people, wounded thousands and ravaged much of the capital.
