Turkey scrambled fighter planes to force a Syrian passenger jet to land and seized what it suspected was military equipment being ferried from Russia to Syrian President Bashar al-Assad's forces.
The interception drew strong protests from both Syria and Russia. Later reports said the Turks had found military communication equipment on board the aircraft.
The interception of the Syrian Air plane came hours after Turkey's chief of staff warned that his troops would respond with greater force if shells from Syria continued to hit Turkish territory.
Military jets escorted the Damascus-bound Airbus A-320, which was carrying around 30 passengers from Moscow, into
Ankara airport late on Wednesday after Turkey received intelligence that it was carrying military supplies.
The plane and its passengers were allowed to continue after parts of the cargo were seized.