The fire at a Miami-Dade waste recycling facility in Doral was at the Covanta site, NBC News 6 - South Miami reported. It started a little after 2 p.m. on Sunday and quickly spread to four buildings.

More than 200 firefighters have been involved in putting out the blaze, with no injuries reported.

The news reported that officials said a conveyor belt may have started the fire, but it is still under investigation.  Fire officials have performed constant air quality checks, and so far, tests have come out clear.

Miami-Dade County Mayor Daniella Levine Cava issued a statement asking residents who live in the area to remain indoors with windows closed if they can. Levine Cava said that both Miami-Dade Fire and Miami-Dade Police responded to the fire and will continue to monitor the situation.

The news reported that Miami-Dade Fire Rescue Chief Ray Jadallah said there are a total of 11 buildings at the facility and four caught fire. He said crews encountered many challenges while trying to get the fire under control.

"The buildings are basically sheet metal all around, the walls, the roof. The scaffolding and catwalks are also made of metal so when we first arrived those areas we’d typically walk on to access certain areas were warped,” Jadallah said.

The Miami-Dade County Resources Recovery Facility is owned by the county and operated by Covanta Energy, serving county residents with reliable and sustainable waste management. More than 1 million tons of waste is processed per year at the site, according to the county's website.