Eight people from throughout the Bay Area were arrested Thursday as part of a large-scale prostitution and human-trafficking ring based in Hayward, according to the Alameda County District Attorney's office.

The arrest sweep, which targeted 10 cities including Clayton, Danville and Newark, is a culmination of a year-long investigation by the Hayward Police Department in uncovering a sophisticated ring of brothels where scores of immigrant Asian women were exploited.

Ten women were recovered and all but one was taken into custody as part of the operation.

Investigators estimate dozens of women have been brought into the United States from Taiwan and China, placed on the prostitution circuit in this country and cycled through Bay Area brothels.

In addition to crimes associated with operating brothels, investigators continue to determine the degree to which human exploitation and trafficking is involved in procuring and enslaving the women recovered from these brothels, the Alameda District Attorney's office said in a press release.

Police departments from Oakland, Berkeley, Sunnyvale, Newark, Danville, Clayton and San Jose assisted the Hayward police department in serving search and arrest warrants.

Sgt. Mike Carroll of the Newark Police Department said Newark officers assisted with the operation Thursday morning. He said they recovered two women who were involved in the operation at Chase Suite Hotel on Cedar Boulevard, next to NewPark Mall.

Also involved in the multi-agency operation were the Contra Costa and Santa Clara County sheriff's offices, the California Department of Justice, the Federal Bureau of Investigations, the Internal Revenue Service, the U.S. Attorney’s Office and the Alameda County District Attorney’s Office.

The suspect arrested in Clayton Thursday morning was one of eight people arrested. No suspect names have been released yet.