China's drive for social stability during the Olympic Games has prompted some hospitals in Beijing and Shanghai to lock up psychiatric patients on what had previously been open wards, according to medical staff.

The locking up of people who had been free to leave hospital will fuel complaints that games preparations failed to take sufficient account of the rights and interests of the vulnerable.

A Shanghai Mental Health Centre staffer said open wards were ordered closed days before the games opened on August 8.

One woman said her son's condition had deteriorated markedly after implementation of "Olympic period" measures. The patient was no longer allowed out of the the hospital during the day and home on Fridays, said the woman, who requested anonymity.

"The doctor told me that for the Olympic period there can be no change of ward, no transfer between hospitals and no leaving hospital," she said.

A member of staff at Beijing's 1,369-bed Huilongguan specialised psychiatric treatment centre said open wards had been closed but patients could leave at certain times under supervision.

"We are doing this to ensure the safety of the patients during the Olympic period," the staffer said.

The closure order was condemned by Aizhixing, a health activist group. "We believe this action is a serious violation of the personal rights of mentally ill patients and a severe blow to the Olympic spirit of 'Mutual Understanding, Friendship, Unity and Fair Competition'," it said.

It was unclear whether the order came from the central government or was a local decision and how widely it was being implemented.

Officials at the ministry of health and Beijing and Shanghai health bureaux and the Shanghai Mental Health Centre declined to comment.