COLUMBUS, Ohio (AP) -- Ohio's attorney general says complaints about abuse and neglect in nursing homes have risen this year.

Mike DeWine says his office's Medicaid Fraud Control Unit has opened 131 cases so far this year, compared with 74 in the same period last year.

The Columbus Dispatch reports (http://bit.ly/12ujChr ) that there have been 63 new cases just in the past month.

DeWine announced recently that his office will aggressively investigate nursing homes that provide residents with inadequate or abusive care. He had gone to a Zanesville nursing home in eastern Ohio where his investigators used surveillance cameras to uncover what he called shocking and disturbing treatment of residents.

Investigators had placed the cameras in patient rooms with the knowledge of patients and families, but not the nursing home.

"I believe that the majority of Ohio's nursing facilities are providing excellent care, but not all of them," DeWine said Friday. "We are going after the facilities that cause harm to their residents, and we will use in-room hidden cameras if necessary."

More investigations are underway.