Scores killed in IS attack on Syria's Deir Ezzor

Islamic State group (IS) militants on Saturday killed dozens of civilians and regime soldiers in wide-scale attacks on government-held areas of the eastern city of Deir Ezzor, opposition activists said.

The opposition Syrian Observatory for Human said 85 civilians were killed in the assault that also claimed the lives of at least 50 Syrian soldiers and pro-government militiamen.

Earlier the Britain-based monitor, which relies on a network of sources on the ground, gave a toll of at least 75 regime forces killed in the IS attack but made no mention of any civilian casualties.

It said at said many of the regime forces were shot dead execution style.

IS controls most Deir Ezzor province and the provincial capital with the same name, while the government controls a few neighborhoods in the northern part of the city and the adjacent military airport.

Most of the casualties took place in the area of Baghaliyeh near the northern tip of the city.

The state news agency SANA said IS militants committed "a massacre," killing dozens of civilians in Baghaliyeh village. It did not elaborate.

The Lebanon-based al-Mayadeen TV, which is close to the Syrian government, also reported a massacre and said IS killed 280 people, including women and children, and threw their bodies in the Euphrates River.

It said the group took more than 400 civilians hostage. The reports could not be independently confirmed.

The IS-affiliated Aamaq news agency had reported a large-scale multi-pronged attack on Deir Ezzor that began with a suicide bombing.

Opposition activists said Russian warplanes were carrying out intensive airstrikes in support of government forces in the area.