Kansas City, Mo. ? The FBI and police on Thursday raided 12 businesses and four homes in Johnson County, Kan., in an investigation related to massage parlors, FBI spokesman Jeff Lanza said.

About 175 agents from the FBI, the U.S. immigration office, and from Olathe, Lenexa, Mission and Overland Park police served the warrants.

Lanza said agents are providing social services to people who may have been employed by the businesses.

Court documents related to the case were under court seal Thursday. But a news conference about the investigation is planned by the U.S. Attorney’s office today.

Investigators will be reviewing customer records and video surveillance from the businesses.