According to the UK based Syrian Observatory for Human Rights (SOHR), Islam Army, armed Syrian opposition group, had captured one of the prison buildings which contains women.
This advance came after two days of fierce confrontations with Syrian regime forces at the Eastern Ghouta in Douma city, east of Damascus.
Islam Army attacked on Friday the Tal Kurdi area which is close to the Central Adra prison, east of the Syrian capital of Damascus.
According to the SOHR, there are at least 5,000 detainees, most of them are from opposition, where the prison capacity is not more than 3,000.
The group had released a video online showing bodies of fighters of the Syrian regime in where they said to be Tal Kurdi area.
“The aim of the attack is to control the prison and free the detainees in it, especially women,” sources told Anadolu Agency.
According to Mesar Press, news website, scores of regime forces were killed due to the attacks.
Islam Army, formed in 2013, is one of the main prominent opposition groups in Syria. It is headed by Zahran Alloush and it comprises more than 25,000 fighters.
The civil war in Syria started in 2011 following a brutal crackdown on anti-government demonstrations and later developed into a multi sided conflict between five main factions - the Syrian regime, opposition groups, the Al Qaeda affiliated Nusra Front, ISIS, and the Kurdish YPG militia.
According to the United Nations, the four-year-long war in Syria has left more than 250,000 people dead and 6.7 million internally displaced, while at least 5.4 million have fled the country.