Victims of a mass execution in Saudi Arabia were made to give false confessions obtained under torture, according to media reports.

The kingdom on Tuesday beheaded 37 citizens, nearly all from its Shia minority, with one crucified after death. The United Nations said at least three were minors when charged.

Court documents seen by CNN show that 34 of the men had repeatedly denied the veracity of their confessions to judges trying their case.

Fourteen were convicted of forming a “terror cell” in the city of Awamiya, a Shia heartland in eastern Saudi, after anti-government demonstrations in 2011 and 2012.

Documents from the Awamiya case reveal how the men repeatedly told the court that their admissions were false and had been obtained through torture. In some cases, the suspects said they had provided nothing more than their thumbprints to sign off on confessions which they claimed had been written by their torturers.

“Those aren’t my words,” said one of the accused, Munir al-Adam, during the trial, according to the documents. “I didn’t write a letter. This is defamation written by the interrogator with his own hand.”

The 27-year-old, who was partially blind and deaf, was named as one of the men executed.