Turkey had previously warned Russia about violations to Turkish airspace , and had also warned them off strikes against civilian Syrian Turkmen living along the Turkish border . Russia has steadfastly maintained " throughout its flight , the aircraft remained exclusively above Syrian territory . " In response , Russian president Vladimir Putin stated that the attack was " a stab in the back by the accomplices of terrorists . " The 2015 conflict between Turkey and the PKK broke out following two year-long peace negotiations , which began in late 2012 , but failed to progress in light of the growing tensions on border with Syria in late 2014 , when the Siege of Kobani created an unprecedented wave of Kurdish refugees into Turkey . Some of the Kurds accused Turkey of assisting the Islamic State of Iraq and the Levant ( ISIL ) during the crisis , resulting in widespread Kurdish riots in Turkey involving dozens of fatalities . The tensions further escalated in summer 2015 with the 20 July bombing in Suruç , allegedly executed by an ISIL-affiliated Turkish group against Kurdish supporters . On 21 July , the PKK killed a Turkish soldier and wounded 2 more in Adıyaman . Some PKK supporters then claimed responsibility for the 23 July killing of two Turkish police officers in Ceylanpinar , describing it as a retaliation
20 July bombing in Suruç
2015 Suruç bombing
Spillover of the Syrian Civil War