A smoke shop in Manhattan is at the center of a major drug trafficking network.

The U.S. Attorney's Office has charged Mujahed Ali and Quirino Garcia Diaz with conspiring to distribute narcotics.

Federal agents say the two were part of an operation that was secretly supplying drug traffickers with the tools to cut, press and package drugs, leading them to multiple drug mills across New York and New jersey.

Investigators say both men were arrested Monday at the Inwood smoke shop, where they worked and allegedly operated.

According to federal complaints, the shop sold cutting agents and drug paraphernalia to traffickers, even advising an undercover officer on which substances would "make cocaine shine the most."

Over a month-long investigation, agents say they identified six narcotics mills across Manhattan, the Bronx, and New Jersey and arrested eight traffickers connected to those operations.

Investigators seized bulk fentanyl, cocaine, meth, firearms and equipment used to package drugs.

Ali and Garcia Diaz are set to appear before a federal judge on Tuesday.