Police say five massage parlors in central Fresno were prostitution fronts.

Fresno police served five search warrants at massage parlors in central Fresno Tuesday that detectives say served as fronts for houses of prostitution.

The businesses are on the southeast corner of North First Street and East Dakota Avenue and are part of a complex with a common walkway. Lt. Mark Hudson said the investigation was launched in response to complaints and information about the businesses and the warrants were served after undercover operations by detectives.

Advocates with the Central Valley Freedom Coalition were on scene during the service of the warrants to offer services to victims of human trafficking. There was no information about how many victims sought the services.

This story was originally published May 3, 2017 at 2:49 PM with the headline "Police say five massage parlors in central Fresno were prostitution fronts.."