BEIRUT, Lebanon (AFP) — A Syria war monitor said Thursday the country’s new authorities had arrested a military justice official under the ousted government of president Bashar al-Assad who issued death sentences for people held in the notorious Saydnaya prison.

According to the Syrian Observatory for Human Rights, Mohammed Kanjo Hassan was arrested in the coastal Tartus province, a stronghold of Assad’s clan, along with 20 members of his entourage.

Under the deposed government, Kanjo Hassan issued, according to the Observatory, “thousands” of sentences, including death sentences, for people held in Saydnaya.

Located near Damascus, the Saydnaya complex was the site of extrajudicial executions, torture and forced disappearances, and epitomized the atrocities committed against Assad’s opponents.

Kanjo Hassan headed Syria’s military field court from 2011 to 2014, the first three years of the war that began with Assad’s crackdown on Arab Spring-inspired democracy protests, according to Diab Serriya, co-founder of the Association of Detainees and Missing Persons of Saydnaya Prison.

He was later promoted to chief of military justice nationwide, Serriya said, adding that he sentenced “thousands of people” to death, often in “trials that lasted minutes.”