Federal authorities in New York made two arrests Monday in connection with the establishment of a Chinese-government run police station in Manhattan where officials allegedly monitored pro-democracy activists.

The clandestine station, run by China’s Ministry of Public Security (MPS), was announced alongside a complaint charging 34 individuals accused of working at a “troll farm” run by the MPS designed to target Chinese dissidents online.

While it appears in some cases the office was helping Chinese citizens with services such as driver licenses, consular activities require approval by U.S. authorities, and law enforcement said Monday that the station’s employees were not registered as foreign agents.

“New York City is home to New York’s finest, the NYPD. We don’t need or want a secret police station in our great city,” Breon Peace, U.S. attorney for the Eastern District of New York, said in a press conference.

“Just imagine the NYPD opening an undeclared, secret police station in Beijing. It would be unthinkable.”

Lu Jianwang and Chen Jinping are charged with conspiring to act as foreign agents, which could carry up to five years in prison, as well as obstruction of justice, which carries up to 20 years of jail time. 

Authorities are still not fully aware of all the activities at the station, located in Chinatown, as Jianwang and Jinping deleted information from their phones following initial outreach by U.S. authorities, according to authorities. 

Peace said Monday called the deletion of possible evidence an impediment in the case but noted that authorities had some evidence that MPS directed the station to spy on a California-based pro-democracy activist.

“The secret police station appears to have had a more sinister use,” he said. “The Chinese National Police appear to have been using the station to track a U.S. resident on U.S. soil.

China has been accused of establishing some 100 such stations around the globe, with Ireland, the Netherlands, and Spain taking actions to address them.

The case represents a significant advancement by law enforcement, with the U.S. now the first country to make arrests in connection with China’s overseas police stations.