HANOI, Vietnam >> Amnesty International has called on Vietnam to end what it says is torture and ill treatment against prisoners of conscience.

In a report released Tuesday, the human rights group said prisoners of conscience have to endure including prolonged periods of solitary confinement, beatings and are denied medical treatment.

The report was based on a year of research, including interviews with 18 former prisoners of conscience.

Five of the prisoners told Amnesty International how they spend lengthy periods of time in solitary confinement in dark cells without access to fresh air, clean water and sanitation. There report said some were frequently beaten.

Vietnam says there are no political prisoners in the communist country.