Bashar al-Assad's forces in Syria launched an offensive around Aleppo Friday, in an effort to push back rebel groups that have made gains there. They are aided by Russian air strikes. The move comes as Turkey said it shot down an aircraft that violated its airspace on the Syrian border after sending three warnings. Few details are available about the aircraft, but early media reports quote officials who say it was a drone. The Syrian government, Russia, and the anti-ISIS coalition operate drones in the area, and Turkey has previously accused Russia of violating its airspace.