The heads of state of Turkey, Russia, Serbia and Bulgaria formally inaugurate the TurkStream gas pipelines.
Montenegrins head to the polls to elect a new session to parliament. Neither the ruling pro-Western coalition, dominated by the Democratic Party of Socialists, nor the pro-Russian and Serbia opposition are projected to have a majority.
The United Nations Security Council approves aid deliveries to northwest Syria through one border crossing with Turkey, a day after its authorization for the six-year-long humanitarian operation ended. Russia and China abstain today on this week's fifth attempt to approve this help.
The United States removes NATO ally Turkey from the Joint Strike Fighter program, following the country's acquisition of the Russian S-400 missile system. Turkey had planned to buy 100 F-35 Lightning II jets.
Bulgarian customs agents seize 191 kg of heroin in transit for Belgium and the Netherlands at the border with Turkey. The drugs, with a street value of €6 million, were hidden under tile glue and detected by a sniffer dog.
The Russian ambassador to Turkey Andrei Karlov is killed in a gun attack at an art gallery in Ankara. Russia calls the assassin, 22-year old police officer, Mevlüt Mert Altıntaş, a "terrorist". Turkish Foreign Minister Mevlüt Çavuşoğlu goes to Moscow for a planned trilateral meeting on Syria, saying "the incident will not impact relations between Turkey and Russia".
Turkish F-16 fighter jets shoot down a Russian Sukhoi Su-24 aircraft that had allegedly infringed its airspace near the Syrian border. Russia's Ministry of Defence denies the Su-24 entered Turkish airspace and initially said it was shot down by ground fire over Syria's Latakia Governorate. A video emerged of one pilot killed as local rebel Turkmen fighters shot at him while he was parachuting and a video of his body, while the fate of the other pilot is unknown but is presumed dead. A combat search and rescue mission by Russian forces failed to reach them. It is the first time a NATO member has shot down a Russian plane since the 1950s.
Turkey says a Russian warplane violated its airspace near the Syrian border, prompting the Turkish Air Force to scramble two F-16 fighter jets to intercept it. The Foreign Ministry summoned Russia's ambassador to protest the violation and urged Russia to avoid repeating such a violation, or it would be held "responsible for any undesired incident that may occur".