At least five Advance Urgent Care centers in the Philadelphia region, Scranton, and State College, Pa., have been raided by federal law enforcement agencies.
The raids were conducted as part of an investigation into overprescribing of opioids, according to sources.
Efforts to contact the chain were not immediately successful.
A spokesman for the Drug Enforcement Administration would not comment on the raids. The FBI and U.S. marshals were also involved in the operation.
At the Willow Grove location at 126 Easton Rd., dozens of agents were seen, NBC10 reported.
Locations in the 9400 block of Roosevelt Boulevard as well as Scranton and State College were also subjects of the raid, a source said.
The owner, Mehdi Nikparvar, is the subject of an investigation, a source said. Nikparvar, a physician, was listed as being in custody at the Federal Detention Center in Philadelphia.
In 2015, the Willow Grove and Roosevelt Boulevard locations, along with another in Scranton and one on the 5000 block of City Avenue in Wynnefield, were also raided, 6abc reported at the time.