A large explosion at a commercial building in downtown Los Angeles on Saturday evening drew hundreds of firefighters to the scene and injured at least 11 of them, according to the Los Angeles Fire Department.

They arrived at a commercial building on East Boyd Street in an area near Little Tokyo where smoke had been seen at around 6:30 p.m.

The blaze quickly turned into a major conflagration after the explosion, which left “multiple buildings on fire,” the department said.

A mayday alert was issued, and the fire department said that more than 230 firefighters had been called to the scene and that “a medical branch has been created for treating and transporting injured firefighters.”

On social media, videos and images show thick smoke, visible for miles, rising into the air.

On Twitter, the Los Angeles mayor’s office said that it was “closely tracking this situation as we continue to get more information.”

Gavin Newsom, the governor of California, also on Twitter, said he was “grateful for the brave firefighters and first responders on the scene battling these flames tonight.”

The structure was a “relatively small warehouse-type building” with “heavy storage inside of it,” said David Ortiz, a spokesman with the Los Angeles Fire Department.

It was home to Smoke Tokes Wholesale Distributor, a supplier for butane honey oil, according to the fire department.

The fire took place in a district not far from skid row and the heart of Little Tokyo.

The area is rapidly gentrifying — a mix of senior housing, bars and restaurants, homeless encampments, wholesalers and small industrial facilities.

The severity of the firefighters’ injuries was unknown Saturday night.

This article was written by Aimee Ortiz, a reporter for The New York Times.