HARBIN - Seven local officials are being investigated after the testicles of four inpatients at a nursing home in Northeast China's Heilongjiang province were chopped off, local authorities said on Friday.

They include Wei Mingfu, head of the Zhenxiang Township government in Qinggang County, where the incident happened, Liang Xun, deputy head of the county's civil affairs bureau, and Su Zhanhai, head of the Zhenxiang Township nursing home, according to Zhenxiang's disciplinary watchdog.

The disciplinary watchdog also suggested the township government sack Su and two deputy heads of the nursing home as well as the civil affairs assistant to the township government.

A man tied up four inpatients and removed their private parts with a dull razor at the nursing home on Tuesday afternoon.

Two victims, 53 and 80, lost one testicle each, and another 60-year-old lost both. Two of them were bedridden in the institution, while the third is mentally handicapped. The fourth victim, who lost both his testicles, was not found until Thursday when police carried out a thorough inspection of the nursing home.

The victims identified the perpetrator as a worker at the home, while a staff member there said the man, in his 30s, was also an inpatient for mental illness.

Police have arrested a suspect but have not revealed his identity or motive.

Many Chinese nursing homes are troubled by insufficient beds, funding and poor management.