Evidence of crimes against humanity being committed in Syria goes beyond photos and video footage of the aftermath of an airstrike or the chaos inside a hospital. President Bashar Assad’s regime also systematically detains and tortures people; at least 17,723 people have been killed in custody across Syria between 15 March 2011 and 31 December 2015, according to an Amnesty International report published Thursday.

“The first thing this torture does is take your dignity,” Syrian detention survivor Omar A., a master’s student from Aleppo, told Amnesty researchers. “It breaks the human. I don’t know why, but it does.”

Various wings of the Syrian regime run detention centers and prisons across the country, Amnesty reports. People are regularly arrested, interrogated and imprisoned.

The first thing this torture does is take your dignity … It breaks the human. I don’t know why, but it does. Omar A

Amnesty interviewed 65 torture survivors ― 54 men and 11 women ― between December 2015 and May 2016. Most of them are now in southern Turkey. A handful of others went to Lebanon, Europe and the U.S.

The London-based nonprofit tracked the estimated number of victims in partnership with the Human Rights Data Analysis Group, an independent nongovernmental organization that applies science to the analysis of human rights violations around the world.

The most common experience that former prisoners shared was torture, typically in the form of beatings while blindfolded. Many also recounted instances of sexual harassment and assault.

Torture began upon arrival at one of the facilities, which some referred to as the “welcome party.”

“During this ‘welcome party’ they registered us and took away our possessions and clothes,” recalled Samer, a lawyer who was arrested in 2012 for trying to deliver humanitarian supplies. “They made us strip naked and walk inside the building. They did not spare anyone. I saw an old man being beaten even worse than we were.”

They did not spare anyone. I saw an old man being beaten even worse than we were. Samer

Torture was continuous, used as a key component during interrogations, the report states. Methods included beatings on the soles of the feet, beatings while stuffed into a car tire, beatings while suspended by the wrists or beatings while strapped to a foldable wooden board. Electric shocks were frequent, too.

“Every interviewee said they had been tortured or otherwise ill-treated during at least one of their interrogations, in most cases during almost every interrogation,” the report notes.

Most of these survivors told Amnesty they attempted to “confess” to see if it would help end their suffering. Guards would even make threats against prisoners’ relatives, including threats of rape, in order to extract a confession.

“They had me stand on the barrel, and they tied the rope around my wrists. Then they took away the barrel,” said Shiyar, a journalist. “There was nothing below my feet. They were dangling in the air. After they were done beating me with the wooden sticks, they took the cigarettes. They were putting them out all over my body. It felt like a knife excavating my body, cutting me apart.”

Conditions inside the detention centers are also abhorrent.

“Survivors spoke of prolonged periods of solitary confinement; severe overcrowding in cells; lack of adequate access to medical treatment, sanitation, food and water; being subjected to extreme temperatures; and being held for hours or days in cells containing the bodies of deceased detainees,” Amnesty reports.

Jamaal T., an academic from Aleppo, was taken away in a taxi in 2011. He told Amnesty that the worst part of his detention was the solitary confinement.

AFP via Getty Images A Syrian man shows marks of torture on his back, after he was released from regime forces, in Aleppo in August 2012.

“The cell was as long as my body,” he said. “I could lie down and put my hands out, and touch the walls on all sides. My cell was close to the torture room, so I could often hear the sound of shouting or screaming. I would have to cover my ears with my hands, so that I could fall asleep.”

And although the interviewees are considered the lucky ones who survived the torture, most “continue to face difficulties, in particular with their health, both psychological and physical, long after their release,” according to the report. However, some say the experience has made them stronger.

After they were done beating me with the wooden sticks, they took the cigarettes. They were putting them out all over my body. It felt like a knife excavating my body, cutting me apart.

Some detention survivors have had to flee to other parts of the country for fear of being arrested again. Others have been shunned from their families due to the rape they underwent.

“I lost two years of my life,” said Saad, a student from Aleppo. “My body is disgusting. The doctor said that it’s amazing that I survived, a burst blood vessel can kill in less than 10 days. Only when I went to the liberated areas did I stop feeling afraid. Only then I felt that no one can arrest me, no one can kill me.”

Amnesty is currently barred from conducting research in Syria, it said. It’s recommending that the Syrian regime end the practices of forced detention and torture, and it’s asking the international community to place a higher priority on addressing these issues within the country.

Anadolu Agency via Getty Images Hasan Ahmed, who was imprisoned for six months in Hama, Syria, then fled to Turkey.

The war in Syria began after pro-democracy protests were held in March 2011. It has resulted in more than 250,000 deaths and has created a refugee population of almost 5 million.

And the end is nowhere in sight. Russian-backed Syrian forces continue to battle with rebel groups for control of cities like Aleppo. Islamic State militants are also trying to stake their claim on the war-ravaged country.

Airstrikes are relentless, preventing any aid convoys from even reaching civilians.

Check out Amnesty International’s interactive recreation of the Saydnaya prison.

Read the report in full here.