Six people were charged Dec. 21 in connection with a multimillion-dollar cannabis-growing operation in Romeoville, Cook County Sheriff Tom Dart announced Wednesday.

Cook County sheriff’s police said a family ran a marijuana-growing operation out of two Romeoville homes.

Parents Vinh Thi Nguyen, 51, and Canh Van Tran, 55, and sons Cuong Van Tran, 31, and Chien Van Tran, 29, all of the 1700 block of William Drive in Romeoville, were charged with production of 50 to 200 cannabis plants, a Class 2 felony, according to Cook County police. Bail for each was set at $50,000. A previous report incorrectly listed Chien Van Tran’s address as a Chicago home, Cook County police said.

Additionally, Nghia Tien Dinh, 39, and Hue D. Tuong, 38, both of the 1600 block of Rose Lane in Romeoville, have been charged with production of more than 200 cannabis plants, a Class 1 felony. Bail for each was set at $70,000.

The Cook County Sheriff’s Police South Narcotics Unit learned of the grow operation through a weeks-long surveillance operation and investigations into drug production and trafficking in the Chicago metro area, police said. A search warrant was issued for both Romeoville homes on Dec. 20. A day later, members of the narcotics unit and Romeoville police executed the warrant.

According to the Cook County sheriff’s department, police found 18 cannabis plants inside concealed rooms in the basement of the William Drive home. Police called the setup an “advanced indoor grow operation,” complete with elaborate lighting, ventilation and irrigation systems.

Another 225 marijuana plants were discovered at the second home in the 1600 block of Rose Lane.

Police said additional charges against all six are pending due to additional amounts of harvested marijuana found in the basements of both houses.

All six defendants appeared in a Will County courtroom on Tuesday. Their next scheduled appearance is Jan. 11.

The arrests came a week after another million-dollar Romeoville pot bust. On Dec. 13, Romeoville police seized 36 marijuana plants from a Paladino Drive home and arrested resident Derek Leinweber, who is charged with the manufacture and delivery of cannabis and production of cannabis plants.

The Cook County sheriff’s police also busted a Tinley Park family accused of running a basement marijuana-growing operation in their home.