CRANSTON, R.I. — A monthslong investigation into numerous reports of suspicious activity at six massage businesses in Cranston has resulted in 11 arrests and uncovered evidence of human trafficking and prostitution, police Col. Michael Winquist said in a news release Friday.

Officers with the department’s Special Victims Unit on Thursday executed six court-authorized search warrants at the businesses suspected of providing massage services without a license.

Some of those arrested on the misdemeanor charges may be victims, police said.

“We are actively assisting many of the persons encountered during yesterday’s operation with various resources that will help them escape the situation that was imposed on them,” Winquist said in a statement.

One woman was charged with permitting prostitution.

Police seized “a substantial amount" of U.S. currency along with records and information that will be used in an ongoing investigation of human trafficking, Winquist said.

The federal Department of Homeland Security is assisting the investigation.