Prisoners in Iran’s largest jail have sewn their lips shut in defiance of the regime as hundreds take part in a hunger strike over the surge in executions.

Harrowing footage from inside the Ghezel Hesar jail captured the hunger strike, now in its 16th day, with several prisoners using needles and thread to stitch each other’s lips together to refuse food no matter what, The Guardian reported.

The dramatic act was sparked after six men were sentenced to death on drug charges and transferred to solitary confinement on July 13 — with the regime speeding up executions as some 1,500 people wait on death row inside the prison.

The Islamic Republic has carried out 424 executions so far this year, with most of the hangings brought down on drug-related cases, according to the Oslo-based Iran Human Rights NGO (IHRNGO).

The non-profit and other human rights groups have criticized the executions and accused the regime of cracking down on the most marginalized prisoners on death row through harsh punishments and sham trials.

Many of those on death row for drug-related cases are low-level couriers who took the jobs to try and escape poverty, the IHRNGO has argued.

The hunger strike serves as the only means for the prisoners to highlight the regime’s cruelty as it also goes after political prisoners and protesters in its latest execution spree, said Mahmood Amiry-Moghaddam, the director of IHRNGO.

“By staging this protest, the prisoners in Ghezel Hesar are taking an extraordinary risk,” he said in a statement.

“They know that the authorities can execute them at any moment, yet they have chosen to raise their voices in the hope that the international community will finally hear them and increase the political cost of these executions,” he added.

Iran has hanged at least 26 people linked with the January protests, with the latest two killed on Tuesday after being convicted of killing four police officers during the demonstrations and “waging war against God.”

Many executions take place on Tuesday, leading to the regular “No Execution Tuesday” protests happening in Tehran’s prisons.

The United Nations’ Human Rights Office warns that eight other young men are at immediate risk of execution over the death of security forces in Isfahan’s Shahid Alikhani Square.

UN experts are calling for a moratorium on executions and for the Islamic Republic to put guarantees in place for fair trials and to limit the death penalty to only “the most serious crimes.”

“Executions only add to the violence and grief Iranians have endured,” the experts said in a statement.