By Oana Lungescu BBC correspondent in Brussels

The report may damage Romania's hopes of joining the EU in 2007

The group says the placement and treatment of many psychiatric patients violate international human rights and best professional practice.

The report is a new blow to Romania's hopes of joining the EU in 2007.

The EU has already warned the eastern European country over its failure to tackle corruption and ensure the independence of its judiciary.

'Deplorable conditions'

In a report out on Tuesday, AI concludes that many Romanians are given psychiatric treatment against their will or placed in hospitals on non-medical grounds.

Patients have no means to challenge their placement because the government is delaying the implementation of a law on involuntary psychiatric treatment.

This amounts to "arbitrary detention and denial of fair trial rights", the report said.

AI says patients are often held in "deplorable conditions", with some patients having to share a bed in order to keep warm.

The Romanian government has already ordered an inspection of all psychiatric wards after an earlier report by AI had shown that 18 patients had died of cold and hunger at a hospital in the south of the country.

The new report calls on the EU to ensure that financial assistance granted to Romania to improve its health system is used with full respect for the rights of patients.

Under EU pressure, Romania has significantly reduced the number of children in state institutions.

But AI points out that some of them are simply transferred to psychiatric hospitals, where they are left to languish for the rest of their lives.

Cage-beds

In the 1970s, Romania was the only eastern European country that, like the Soviet Union, put some of its political prisoners into psychiatric wards.

Human rights campaigners say many of the doctors involved in those practices remain in positions of power.

But Romania is not an isolated case.

Two years ago, AI found a similar state of affairs in Bulgarian psychiatric hospitals.

It also criticized the use of cage-beds for psychiatric patients in Hungary, the Czech Republic, Slovakia and Slovenia.