The PKK is a nasty Kurdish Marxist guerrilla group. For years they have battled the Turkish government, but now they have turn their sights on Syria. The PYD which is linked with the PKK has begun to attack forces loyal to Assad in support of the Syrian Islamists. The Syrian forces have attacked PYD positions in retaliation.
Clashes erupted on April 4 between the Kurdish People’s Defense Units (YPG) and Syrian government forces in Qamishli, the unofficial capital of the Kurdish-dominated areas of northern Syria. They were the first such clashes in that city, still under the control of the Bashar al-Assad regime, in Hasakah province.[....]
The clashes have led to speculation that the YPG might abandon its policy of neutrality in the Syrian conflict. They also intensified rumors that tensions between the regime and the PYD are the result of the peace talks under way between the Turkish government of Prime Minister Recep Tayyip Erdogan and the Kurdistan Workers Party (PKK), which has fought the Turks since the early 1980s. The YPG is affiliated with the PYD, which is viewed as the Syrian branch of the PKK.
According to Tejel, “All this is to say that we cannot state that they are ‘enemies’ or ‘allies.’ It depends on the context, the moment, and local relations. In other words, if cooperation between YPG with the FSA is now a reality, it does not necessarily mean that we are witnessing a complete rupture…. Maybe or maybe not.”