A key suspect in one of the most notorious killings of the Syrian civil war has been arrested, Syria's interior minister has said.

Amjad Youssef was wanted over the mass killing of civilians in April 2013 in the Tadamon district of Damascus.

Footage emerged in 2022 showing Syrian soldiers leading victims, bound and blindfolded, to a pit before shooting them. The video became one of the most direct pieces of visual evidence of extrajudicial killings by then government forces.

Interior Minister Anas Khattab said Youssef was the main perpetrator of the massacre and was taken into custody after a "well-executed" security operation.

Syria's state news agency said he was detained in Hama province.

Footage published by the UK-based monitoring group the Syrian Observatory for Human Rights (SOHR) appeared to show Youssef after his arrest, sitting in a police car, his nose and forehead bloodied.

The killings at Tadamon attracted widespread attention after video, filmed by the perpetrators, showing it taking place was leaked nine years later.

In the film, victims are seen being led one by one to the pit and shot. It was one of several mass killings in Tadamon by government forces around that time.

Human Rights Watch (HRW), which has visited the site, said there was evidence that 288 were killed in Tadamon, 41 in the incident in April 2013.

It said 11 blindfolded victims shown in the video were shot at close range and pushed into a machine-dug grave.

It has called the area "a huge crime scene".

HRW senior researcher Hiba Zayadin said the leaked video "filmed by the perpetrators themselves who laughed as they killed their victims, shows the [former] Syrian government's callous disregard for people's lives.

"This massacre is just one horrific incident in a pattern of state violence and apparent war crimes."

The government at the time, led by President Bashar al-Assad, was toppled by rebels in December 2024. Assad's forces had fought jihadist and rebel groups in the civil war which began in March 2011 when security forces cracked down violently on peaceful pro-democracy protests.

More than half a million people were killed in over 13 years of conflict which followed.