Turkish military jets have forced a Syrian passenger plane to land at Ankara airport.
The Airbus A-320 was flying from Moscow to Damascus.
Turkish officials suspected its cargo could include Russian weapons for the Syrian regime of Bashar al-Assad.
The Airbus A-320 with 37 passengers and crew was later allowed to leave, although some of its cargo was seized.
According to ITAR-TASS, Russia was to demand that Turkey explain the circumstances surrounding the incident.
Shortly after the Syrian plane was intercepted, Ankara warned Turkish airlines to avoid Syrian airspace, as it was unsafe.
Meanwhile, Turkey's military chief warned of a more forceful response if shelling continued to spill over the border. Necdat Ozel was speaking as he toured the Turkish border town of Akcakale, the site of a Syrian mortar attack last week that killed five civilians.
Turkey has bolstered its military presence along its 900-kilometer border with Syria.
Over the past week, Turkish forces have responded to gunfire and shelling coming across from northern Syria, where forces loyal to Assad have been fighting rebels for control of large patches of territory.
On October 9, NATO Secretary-General Anders Fogh Rasmussen said the 28-member military alliance had plans in place to defend Turkey.
He gave no further details, but a senior U.S. defense official said NATO would likely react if Turkey made a request for assistance.
U.S. Defense Secretary Leon Panetta, meanwhile, announced U.S. military personnel were now in Jordan to help the government contend with Syrian refugees, bolster its military capabilities, and prepare for any trouble with Syrian chemical weapons stockpiles.
In Damascus, the Syrian government said that an appeal by UN Secretary-General Ban Ki-moon for a cease-fire was only acceptable if the rebels agreed to abide by it, too.
With reporting by dpa, Reuters, and AP