A Syrian man died from a heart attack after he saw a photo online of the moment his son was tortured and killed by the Bashar Assad regime.

Nadir Abbud of northwestern Syria's Idlib province had not received any news from his son Yunus since the regime arrested him seven years ago.

The father confirmed the death of his missing son through photos shared on the internet.

Hundreds of thousands of Syrians searching for their relatives have stepped up their efforts after the United States adopted the Caesar Act, a law that imposes sanctions on the Syrian regime for war crimes.

Families who have long given up on ever finding their relatives click on web links where photos of those killed in regime prisons are posted in a desperate attempt to confirm the deaths of their loved ones.

Imaduddin Rasit, the founding member of a France-based association monitoring Syrian casualties of war and prisoners, said more than 6,000 photos of people tortured to death have been shared on the internet.

The photos were first shared in March 2015.

He said their official webpage was visited by nearly a million people following the implementation of the Caesar Act and more families were getting in touch with the association.

He noted that his association published up to 60 photos in February that had not been shared before, taking precautions in light of the sensitivity surrounding the issue.

The Caesar Act is named after a military forensic photographer code-named "Caesar" who leaked photos of people tortured to death in Assad prisons in 2014. The act came into force as of June 17.

The photos taken by "Caesar" were first published by Anadolu Agency in 2014 and made a tremendous impact globally in the sense of proving the war crimes committed by the Assad regime, including systematic torture and starving to death of prisoners.

On Dec. 18, 2019, the U.S. Senate adopted a draft law envisaging additional sanctions on people and organizations aiding activities of the Assad regime and its supporters, including Russia and Iran.

On Dec. 21, U.S. President Donald Trump signed the Caesar Syria Civilian Protection Act, which was included in the country's 2020 defense budget.

Syria's civil war, which started with the brutal repression of anti-government protests, has killed more than 380,000 people and displaced nearly half the country's pre-conflict population.

The U.K.-based Syrian Observatory for Human Rights monitoring group estimates that at least 100,000 people have died from torture or as a result of horrific conditions in government prisons.

Already in 2012, Human Rights Watch said Syria was holding tens of thousands of detainees in a "torture archipelago."

It documented 27 detention facilities nationwide used to hold people swept up in the government's crackdown on protesters.

Witnesses described torture, including beatings, the use of electricity or car battery acid, sexual assault and mock executions.

Back in June 2019, the Syrian Human Rights Network (SNHR) announced that over 14,000 civilians have died of torture since the beginning of the civil war in Syria in 2011.