Saudi Shiites in Qatif in Saudi Arabia’s Eastern Province protest the execution in Riyadh of prominent Shiite cleric Nimr al-Nimr by Saudi authorities on Jan. 2, 2016. (AFP/Getty Images)

Munir al-Adam spends his hours alone in a Saudi prison, his mother says. He doesn’t know if it is day or night because he is kept mostly in a dark cell. Partially blind and partially deaf, he has experienced different forms of torture in the five years since his arrest.

“He has been ordered to stand for long intervals of time,” said his mother, Zahraa Abdullah. “He was beaten with sticks and cables. He was electrocuted and prevented from eating or going to the bathroom.”

Adam and 13 other Saudi men are facing execution any day now for allegedly staging protests in the kingdom. All from the country’s Shiite minority, they include a teenager who was arrested just before he was to board a flight to visit a U.S. college where he planned to study English and finance.

The men were charged with terrorism-related offenses. But human rights activists and American academics say confessions from the defendants were extracted under torture and that the death sentences breach international law. Activists have launched a public appeal to Saudi Arabia’s new crown prince, Mohammed bin Salman, to dismiss the sentences.

Saudi Justice Ministry officials said Thursday that they planned to issue a statement soon about the cases. Saudi officials have said previously through state-run media that the men staged attacks on checkpoints and patrols, killing several members of the security forces.

The sentences are a sign of the deepening tensions between Saudi Arabia’s Sunni elite and Shiite Muslims at home and in the region. In neighboring Yemen, the kingdom is engaged in a costly war against Shiite Houthi rebels said to be backed by Iran’s Shiite theocracy, Saudi Arabia’s top regional rival. The Saudi-led campaign to isolate Sunni-led Qatar is partly over the Persian Gulf nation’s close ties with Iran.

At home, Shiites have long complained of discrimination. As the Arab Spring revolts erupted six years ago, thousands staged demonstrations mainly in eastern Saudi Arabia’s heavily Shiite-populated regions to demand more rights and access to government services.

But the kingdom’s rulers viewed the uprisings as a threat, accusing protesters of aligning themselves with Iran. In recent weeks, confrontations between Shiites and government forces in a restive eastern area have grown more violent.

The 14 men on death row have been charged with offenses related to attending demonstrations. They were sentenced by the Specialized Criminal Court, which, according to the Britain-based human rights group Reprieve, “used confessions extracted through torture as the basis of convictions.”

For more than a decade, Saudi Arabia has been among the top five countries globally for the large number of executions it carries out, mostly through beheadings and stonings. More than 300 people have been executed in the past two years, human rights activists say. The death penalty is regularly imposed for nonviolent crimes, including drug possession and adultery.

Two weeks ago, the 14 men were moved to the Saudi capital, Riyadh, a sign that their executions were nearing. At least one juvenile and several young protesters are among the group, according to Reprieve. They include Mujtaba’a al-Sweikat, who was arrested at an airport in December 2012 as he was leaving the country to visit the campus of Western Michigan University.

Sweikat, 17 at the time, was not given a reason for his arrest and has been in prison ever since. He was convicted without having access to legal representation, according to human rights activists.

In a July 22 statement, faculty and administrators of Western Michigan University said Sweikat was “subject to sleep deprivations, beatings, cigarette burns, solitary confinement and others forms of torture or suffering.” He was sentenced to death “on the sole basis of a confession extracted by torture,” they added, citing the findings of the U.N. human rights office

“President Donald J. Trump and other U.S. officials should be robust and vocal in defending freedom of expression the world over,” read the statement. “If U.S. citizens stay silent as another country attacks this freedom, we undermine the very foundations of democracy.”

Adam was arrested in March 2012 at a shop in the eastern town of Awamiyah. Police accused him of confronting them and took him to jail. He was 18 at the time and was tortured in his first three months in detention, said his mother, who answered questions via text messaging. She last spoke to him in June, during the Muslim holy month of Ramadan.

Now, every day is consumed by one fear.

“The date of the execution is not known,” she said. “I call upon every influential person to save my son’s life.”

Heba Farouk Mahfouz in Cairo and Sheikha Aldosary in Riyadh contributed to this report.