VIDEO: Fierce fighting rocks southern Syria as Islamic State moves on rebels

Western Deraa has seen fierce fighting between an Islamic State (IS)-linked group and Syrian rebels in recent weeks as IS has tried to push farther south into Syria than ever before. 

The Yarmouk Martyrs Brigade managed to make inroads in the southern Deraa province last week after seizing the Wadi Yarmouk basin, putting pressure on the Free Syrian Army (FSA) forces that have been working to push back the IS-linked group.  

Middle East Eye has obtained footage from the frontlines, showing tanks and heavily artillery fire. Southern Front fighters, often seen as some of the more secular elements of the opposition, told MEE they would fight to the death to ensure IS did not enter their territory. 

The pushback by rebel forces has in the past week successfully stalled the Yarmouk Martyrs Brigade's advance, with anti-IS forces capturing the al-Anfah checkpoint and the towns of Tel Kawkab and Tel Kharba.

Fighting has caused thousands of families to flee towns in Deraa and head to the Zizoun valley near the Jordanian border, residents said.

On Monday, when MEE was able to get rare access to the FSA frontlines, fighting was still raging around the town of Hayt, with the Yarmouk Martyrs and the Nusra Front shelling each other's positions.

Ahrar al-Sham units in Hayt announced they had killed "dozens" of enemy fighters as they rebuffed a major IS attack on the town some 20 kilometres from the provincial capital of Deraa. However, casualties were reported on both sides, and Abu Salah al-Masalma, Nusra's general military commander in Daraa, is said to have been killed.

The Nusra Front is seen as al-Qaeda’s affiliate in Syria and has a complex relationship with main opposition groups in the south that have admitted to coordinating but not directly fighting with the group deemed to be a terrorist organisation by the UN.

The offensive by IS-linked groups began last week when the villages of Tseel and Adawan in western Deraa fell after fierce fighting.

Eyewitnesses from the area then said it was the first time IS had raised its black-and-white banners in the southern province.

Locals in Tseel told MEE that IS fighters had executed a number of residents and had asked other opposition fighters to surrender their weapons and turn themselves in or pledge allegiance to IS.