Three people were charged in connection with running a human-trafficking and prostitution operation at four massage parlors in Montgomery County, officials said.

Hong Wang, 56; Xiaoxia Lin, 42; and Hanfeng Zhang, 55, have been arrested and charged. All are from Germantown, Md.

Montgomery County Police said they learned in December 2017 of a possible prostitution and human-trafficking operation at four massage parlors — two were in the 900 block of Hungerford Drive in Rockville, one was in the 7200 block of Muncaster Mill Road in Derwood, and another was in the 20 block of South Frederick Avenue in Gaithersburg.

The parlors are owned and operated by Lin, Wang and Zhang, police said.

In their investigation, police said, they found two women from New York who were living at an apartment in Gaithersburg. Police detectives saw Lin drive the women to the parlors to work and learned through interviews that the women were often providing “sexual services” to male customers.

On June 12, detectives got warrants for the three, and they were arrested. Lin and Wang were being held on a $25,000 bond. There was no immediate bond information for Zhang, according to police.

Officials said there may be other victims in the incident.