SPRINGFIELD — Two men from Chicago and Brooklyn, New York, were arraigned Friday on federal charges linked to a series of large marijuana grow operations in Palmer and Monson.

Weiqing Li, 41, and Li Qin Li, 49, were charged in late July in U.S. District Court with manufacturing marijuana and processing marijuana with intent to distribute.

Both pleaded not guilty to the charges through an interpreter. Weiquing Li, of Chicago, told agents he moved to Massachusetts around February for the sole purpose of growing weed, prosecutors said. Li Qin Li came from Brooklyn.

The men were released on bail and traveled back to their home states after detention hearings earlier this month.

The two Chinese nationals were arrested after federal agents busted the alleged grow ring, which had apparently been under surveillance by law enforcement for months, according to Assistant U.S. Attorney Catherine Curley.

Agents with the U.S. Drug Enforcement Administration executed search warrants at two residences in Palmer, two residences in Monson and one warehouse in Monson, seizing more than 4,000 marijuana plants in what they characterized as a “large, commercial-style grow operation.” Along with the plants, agents found elaborate systems for lighting, cooling, irrigation and ventilation systems, according to court records.

The pair were among four Chinese nationals arrested recently in connection to large grow operations in rural communities in Western Massachusetts. Also on July 29, utility workers responded to a home in Savoy in response to what appeared to be a “safety issue” at a home at 72 Jackson Road.

A man who said he only spoke Chinese answered the door and tried to shoo the workers away by stuffing a wad of $100 bills in one’s front pocket. The house had been logging $10,000 monthly electricity bills and Eversource workers found charred electrical boxes around the property, according to Massachusetts State Police troopers.

That agency said it uncovered a $3 million marijuana grow operation there. Two men, Yebin Mai, of Staten Island, New York, and Bin Huang, of Brooklyn, were arrested days later. They were arraigned in state court and held on $100,000 bail, police said.