Beirut, Ankara – While opposition factions were busy fighting each other on Friday, Syria’s regime forces and their allies succeeded to advance in the Qaboun district at the outskirt of Damascus.

Fierce clashes ripped through several towns in the rebel-held eastern Ghouta region between Jaish al-Islam and both Faylaq al-Rahman and Hay’at Tahrir al-Sham as the two sides exchanged accusations regarding which group had first kicked off the fighting.

Opposition factions clashed on Friday mainly in Erbeen and Kafr Batna, causing a number of casualties and injuries, including the military commander of Faylaq al-Rahman and the Hay’at Tahreen al-Sham emir in the city of Erbeen.

Also on Friday, regime forces controlled houses located on the outskirts of the eastern part of the Qaboun district together with achieving a similar advance in the southern part of the area, according to reports published by the Syrian Observatory for Human Rights.

The Observatory said regime forces launched 25 surface-to-surface missiles at several areas in the Qaboun district since early Friday morning, while clashes continued around the district’s outskirts.

It also reported that up to 40 fighters from all the warring parties have been killed and wounded in Friday’s clashes.

Separately, Turkish President Tayyip Erdogan escalated on Friday his position against the People’s Protection Units (YPG), prior to his visit to Moscow expected next Tuesday and to Washington in mid-May.

Speaking at an energy conference in Istanbul, Erdogan said his country “will not allow efforts to create a terror corridor in our southern border,” adding that Washington’s support for Kurdish YPG fighters damaged “the spirit of solidarity” with Turkey.

The Turkish president however asserted that a new page could be turned in ties with US President Donald Trump.

“I am seeing signs that Trump…will display a more decisive stance in the fight against terrorism and in ending state terror in Syria,” he said.