At least one man was arrested after law enforcement raided a house in the Bronx and discovered 12 kilograms of fentanyl on Tuesday afternoon, according to a report and law enforcement sources.

Authorities descended on the clandestine drug lab in a Belmont apartment building around 3 p.m. and a 66-year-old man was taken into custody, according to cops and sources.

Twelve kilos of fentanyl were found inside the home, News 12 reported.

Eight cops from different agencies that participated in the raid were treated for minor injuries, the FDNY said. Another two people were also treated.

At least one detective was exposed to the dangerous drug, sources said.

An FDNY hazmat team was working the scene at 780 Garden Street into Tuesday night after the incident was initially reported as a fentanyl spill.

The building where the raid took place also houses two daycares, authorities said, according to News 12.

No children were reported hurt.