Britain has discovered disturbing evidence related to PYD’s coordination with the Syrian regime and Russian air forces in Syria, the United Kingdom Foreign Secretary Philip Hammond said on Tuesday.
"What we have seen over the last weeks is very disturbing evidence of coordination between Syrian Kurdish forces [YPG], the Syrian regime and the Russian air force which are making us distinctly uneasy about the Kurds' role in all of this," Hammond said during his speech in British Parliament.
YPG is the armed wing of PYD, which is considered by Turkey as the Syrian extension of PKK, which is listed as a terrorist organisation by Turkey, the US and the EU.
With the help of Russian air strikes, YPG militants have recently been making advances in opposition-held areas in northern Syria despite warnings made by Turkey and other allies to stop.
Turkey has also been hitting YPG in northern Syria since the militant group attacked Turkish military positions recently.
However, while Turkey has shelled YPG positions, the US-led alliance has backed the group in Syria, with the US describing it as a “reliable partner” in the fight against DAESH.