Law enforcement officials say authorities raided and found fentanyl at a suspected pill mill in Belmont on Thursday evening. 

Sources say the pill mill is located at 2337 Beaumont Ave. in the Bronx. Four people have been arrested. The amount of fentanyl found has not been specified.

Multiple investigators have been spotted entering and exiting the address wearing masks and hazmat suits.

Multiple law enforcement agencies are taking part in the ongoing investigation including the NYPD, DEA, and Homeland Security.

"To be so close to a home, you wouldn't even imagine that this is happening from there because you never seen it, you never seen any craziness going in and out," said neighbor Theresa Pinto. "My children are right here, this is my daughter right here... when is this going to stop, when is all this going to get cleaned up?" 

Other drugs and two industrial pill presses were found at the location, according to sources. The home where the raid took place is located nearby a Bronx day care center.