Palestinian young man Shadi Mohamed Amarein has died under torture in Syria’s state-run lock-ups, where he had been forcibly disappeared for four years.

The Action Group for Palestinians of Syria (AGPS) said in a statement that Shadi’s family was recently updated about his death in Syrian regime prisons.

Shadi, a resident of Duma in Rif Dimashq province and a native of the Palestinian village of Tira in Haifa, was arrested at a security checkpoint south of Syria and dragged to a detention center in Damascus.

His death brings the death toll of torture among Palestinian refugees in war-torn Syria to 621.