Disturbing cellphone video appears to back up a teenage Syrian boy’s tales of beatings and torture at the hands of Islamic State militants, the BBC reported Monday.  

The 14-year-old boy -- identified only by his first name, Ahmed -- says he was blindfolded and suspended about a foot off the ground by his wrists as ISIS extremists beat him.  

Ahmed was selling bread in the ISIS-controlled northern Syrian city of Raqqa to help support his family, when two men he knew asked him to put a bag near an ISIS meeting place. He says he was duped into planting a bomb.

Extremists then captured him and held him for two days, torturing him until he gave them information.

"I thought I was going to die and leave my parents, my siblings, my friends, my relatives all behind,” Ahmed told the BBC.

"They started lashing me, electrocuting me in order to confess. I told them everything," he said.

The cellphone video of Ahmed’s beating was taken by an ISIS defector. It shows the boy blindfolded, as two masked men, dressed in black, pace in front of him. One has a knife and a gun, the other walks around the room with an AK-47.

Ahmed was arrested for his part in the bombing and sentenced to death. But his executioner took pity on him, and let him escape. He is now in Turkey, but still traumatized by his experience.

"When they electrocuted me, I used to scream, calling for my mother," Ahmed said in the BBC interview, only showing his eyes, so as not to reveal his identity.

"But as soon as I did, [one of the torturers] used to up the voltage even more. 'Don't bring your mother in it,' he used to say," Ahmed remembered.

"It's rare that I'm able to sleep," he explained. "When I first came to Turkey, I used to have nightmares all the time. I got some treatment. But I couldn't sleep --- I used to dream about it all the time.”

The defector who filmed Ahmed's beating says the video was made for propaganda purposes, and he didn’t know the fate of two other victims shown. The unidentified man says he is now full of remorse.

"I am regretting every moment," the man said. "When I joined ISIS, I wasn't convinced of it, but I had to. Although I wasn't particularly heavy-handed with people, I hope that the people I hurt will forgive me," he added.

Inside its self-declared caliphate, ISIS has eliminated secular education and created military-style schools which indoctrinate children and train them to kill. ISIS propaganda videos show children, some barely teenagers, undergoing drills and learning to shoot, the BBC reported.

The UN has accused ISIS and other armed groups in Syria and Iraq of torturing and killing children.

Children have reportedly been shown in beheading videos, and also taking part in killings.

"They pretend they're religious, but they're infidels. They used to smoke. They pretend to be enforcing the rules of Muslims, but they're not. They hit and kill people," Ahmed said.