Turkey shelled Afrin on Friday amid reports Russian military observers were withdrawing from the Syrian-Kurd canton, in a move that would allow Turkish forces to launch a ground assault on Kurdish militants.

Russia has based military observers in Afrin since 2015, and the subject of their removal was part of negotiations between Turkey and Russia yesterday over what the Turkish president, Recep Tayyip Erdogan, said was a matter of national security.

Turkish media reported that approximately 180 Russian observers were pulling back from their positions on the Afrin/Turkish border, hours after Turkish artillery began what Ankara said was the “de facto” start of operations against members of the Kurdish YPG militia, which it considers part of the PKK terrorist group.

The Turkish reports have not been confirmed by Russia.