Amnesty International says more than a dozen political prisoners have gone on hunger strike in a prison in Karaj, northwest of the Iranian capital, Tehran, to protest the “cruel, inhuman, and degrading conditions” they have been forced to endure.

In an August 22 statement, the rights group said that the prisoners at Rajai Shahr prison were recently transferred to a newly opened area where conditions are so poor that they have been described as “suffocating.”

According to Amnesty International, prisoners are held in cells with windows covered in sheet metal and deprived of access to clean drinking water and food.

The prisoners are also barred from having family visits and denied access to telephones, the human rights watchdog group said.

“The fact that detention conditions have become so poor that desperate prisoners feel they are forced to go on hunger strike to demand the most basic standards of human dignity is disgraceful and highlights the urgent need for reforms to Iran’s cruel prison system,” Magdalena Mughrabi, deputy Middle East and North Africa director for Amnesty International, said.

She called on Iranian authorities to “urgently” ensure that all prisoners at Rajai Shahr have access to food, drinking water, medicine, health care, and sanitation.