Federal authorities charged four people with bringing women from China to the Kansas City area for prostitution after a series of raids at businesses billed as massage parlors.

The charges were brought Friday, a day after authorities say they rescued from 15 women from 12 businesses in Johnson County, Kan., mostly at strip malls.

The businesses had drawn the attention of neighbors for some time, investigators said.

Those charged were Ling Xu, 45, Zhong Yan Liu, 35, Cheng Tang, 21, all Chinese citizens living in Overland Park, Kan., and Hongmei Madole, 31, a native of China married to a U.S. citizen and living in Olathe, Kan.

They were charged with transporting people across state lines and national borders for the purpose of prostitution.

The women are not facing charges, FBI spokesman Jeff Lanza said.

The defendants made an initial appearance Friday afternoon in U.S. District Court in Kansas City and asked the court to appoint attorneys.

Bond for Madole was set at $50,000. U.S. Magistrate Judge Robert Larsen set a hearing for Tuesday to determine bond for the other three defendants and to decide if the case will be sent to a grand jury.

A criminal complaint filed Friday alleges that the defendants brought women across national borders and state lines, including into Kansas through Missouri, for prostitution for more than a year.

U.S. Attorney John F. Wood said investigators believe the massage parlors were "in fact, nothing more than a front for highly profitable and thriving prostitution organizations."

He said an 18-month investigation involving local, state and federal authorities found that the women were brought from China into the United States, primarily San Francisco, Los Angeles and New York City. They then flew to Kansas City and were driven to Johnson County, Kan., Wood said.

An undercover officer visited three of the businesses several times between January and May and was solicited to engage in sexual acts with women there each time, according to an affidavit filed with the criminal complaint.

The affidavit says investigators also searched trash at two of the businesses and found evidence of airline flights to Kansas City from Los Angeles, Phoenix, New York City and Las Vegas.

The defendants also were found to have wired a total of $83,300 to China, according to the affidavit.