ISIS has killed a total of 2,900 civilians since the militant group announced its "caliphate" in Syria, a report by Syrian Observatory for Human Rights (SOHR) revealed on Tuesday.
IS militants killed a total of 5,170 people in Syria including civilians, rival militants and army personnel. Islamic State had declared a self-styled caliphate in June 2014.
According to SOHR, Islamic State's control in Syria has decreased by 3 per cent after they lost large swathes of areas to the Syrian army and US-backed Syrian Democratic Forces (SDF).
The Islamic State has control over few areas in the eastern countryside of Homs province, the southeastern desert of Deir al-Zour province, an area on the eastern bank of the Euphrates River and a pocket in the northern countryside of Deir al-Zour in eastern Syria.
The Islamic State also controls few areas in the Yarmouk area in the countryside of the southern province of Daraa as well as pockets in the southern countryside of Hasakah province in northern Syria.
Despite losing areas measuring tens of thousands of kilometers, IS continues to shade blood in Syria, said the Observatory.
It was also revealed that IS carried out executions of civilians and rival fighters over the past two months.
The Syrian army had captured its strongholds in the Hajar al-Aswad and Yarmouk Camp and defeated them in southern Damascus.
The SDF has also recently launched an offensive on IS east of Euphrates, but the Observatory said the SDF failed to storm Hajin area, the last IS stronghold east of Euphrates and moved the military operation to the southern countryside of Hasakah.
The Syrian army said it had foiled an attack last Wednesday by the IS group on a Syrian military site in Deir al-Zour, killing 43 IS militants, while four Russian experts were also killed in the showdown.
The Observatory revealed that it relies on a network of people on the ground. It also revealed that the battle between IS and the Syrian army in the countryside of Deir al-Zour, as the terror-designated group has attempted to distract the army by waging sudden attacks.
