A/HRC/22/59 The Al-Tawhid Brigade which formed before the anti-Government armed groups’ campaign in Aleppo represents the most advanced attempt yet in uniting local brigades under a single command hierarchy. Some others like the Union of Homs Rebels have even tried to establish a governance structure including military, security, judicial and administrative components to fill the gap left by Government authorities in “liberated areas”. D. Salafi groupsa 17. Increasingly radical ideologies are gradually defining the character of the conflict. The accompanying radicalisation favours armed groups that openly adopt Salafism. The AlNusra Front stands out among these groups due to its superior level of operational effectiveness and its use of more aggressive tactics clearly benefiting from better financial support. Other independent Salafi groups, like the Ahrar Al-Sham Battalions in Idlib and the Al-Islam Brigade in Damascus eastern suburbs have also attracted more radical elements of the opposition and subsequently gained more legitimacy among the opposition armed groups. 18. Foreign fighters constitute an important faction of the insurgency but their numbers and organisation are still hard to assess with accuracy. It is sure that they represent a small proportion within the anti-Government armed groups’ ranks but their expertise and experience in matter of IEDs and insurgency warfare have brought a substantial contribution to the opposition’s tactical effectiveness. They have integrated armed groups all over the country and contributed to the radicalisation of anti-Government insurgents. According to several statements, foreign fighters are drawn from countries in the Middle East, North Africa and Central Asia, many from Libya, Tunisia, Saudi Arabia, Lebanon, Iraq and Egypt. E. Other forces 19. The predominantly Kurdish areas of Syria have been marked by mounting tensions between the PYD and anti-Government armed groups. The newly created Kurdish Popular Protection Units, commonly known as the YPG, responsible for maintaining order and protecting the lives of residents in Kurdish neighbourhoods have captured most of the Kurdish towns in the North, as Syrian security forces withdrew without any major resistance. Since July, clashes have periodically erupted in Aleppo Kurdish neighbourhoods and other Kurdish towns between the YPG and the Free Syrian Army because of the latter’s intrusions into Kurdish territories. a GE.13-10627 Salafi refers to a wide range of groups who adopt a literalist view of Sunni canonical texts. In Syria it often denotes groups who use that literalism to promote a militant activism against a ruling establishment deemed non-Islamic. 41