Los Angeles County firefighters are battling a two-alarm blaze at a recycling center in Pomona.
The fire was reported about 6:30 a.m. off East 1st Street and San Antonio Avenue, an industrial area of Pomona south of the 10 Freeway, said Los Angeles County fire inspector Scott Miller.
"It's going to require a lot of manpower," Miller said.
The fire was upgraded to a two-alarm within moments of the first crew arriving at the scene, he said. KTLA reported explosions were heard coming from inside the recycling yard.
The blaze was burning through part of the recycling center's main building, stacks of aluminum outside and containers outside, Miller said.
A hazmat team and an urban search-and-rescue vehicle were aiding between 40 and 50 firefighters in putting out the flames, which Miller estimated would be extinguished before 9 a.m.
"There's some prevailing winds that are making the smoke drift a bit, but it's not really impacting the area," Miller said.
Firefighters were attacking the blaze from atop aerial ladders, he said.
The cause of the fire and where it started remained under investigation, he said. No injuries had been reported.