(VOVworld)- The relationship between Russia and Turkey has been tense since Turkey shot down a Russian Su 24 fighter. Tensions increased further on Friday when Ankara said another Russian Su-34 fighter jet crossed into Turkey's airspace despite several warnings not to violate Turkish airspace in both Russian and English.

Russian SU-34 fighter bombers are based at Hmeymim airbase in Syria- Photo: Reuters

The Russian SU-34 jet crossed into Turkish airspace along the Mare- Jarrablus route where Turkey and a US-led coalition are fighting IS.

Ankara said on Saturday that it had summoned the Russian ambassador over the violation of Turkish airspace. Turkish Prime Minister Ahmet Davutoglu said Turkey will closely monitor its space and deal with all violations. Turkish President Recep Tayyip Erdogan warned of retaliation against Russia if such actions continue and accused Russia of deliberately escalating tensions between the two countries. He said he is prepared to meet President Putin to discuss the issue.

NATO Secretary General Jens Stoltenberg called on Moscow to be cautious in flight management and to respect NATO airspace. Moscow’s action has further destabilized its already unstable relation with NATO. Mr. Stoltenberg urged the two sides to remain calm and refrain from retaliatory actions.

The Russian Defense Ministry said Saturday that no Russian aircraft has violated Turkish airspace, adding that neither Russian air defense in Syria, nor Syrian radar had detected any crossing violations of the Turkish border by a Russian Su-34 warplane and called Turkey's reports of an alleged violation of Turkish airspace by a Russian Su-34 unfounded "propaganda", Russian Defense Ministry spokesman Maj. Gen. Igor Konashenkov said there were no violations of Turkish airspace by aircraft of the Russian air group in the Syrian Arab Republic. He said the radar used was unable to determine the type or affiliation of an aircraft — whether it belonged to Russia or to the US-led coalition. He said neither Russian air defense systems in Syria nor Syrian radar stations had detected any violations of the Turkey-Syria border.

On November 24, a Turkish F-16 fighter shot down a Russian Su-24 bomber with two pilots on board over Syria. In response to Ankara's "stab in the back," as the incident was described by Russian President Vladimir Putin, Moscow imposed a number of economic sanctions on Turkey.