BEIRUT, Oct 6 : NATO's chief accused Russia on Tuesday of deliberately violating Turkey's airspace during bombing raids on Syria, as Ankara summoned Moscow's envoy over the latest intrusion.
The rise in tensions came as Russian warplanes struck Islamic State group targets in and around the ancient city of Palmyra for the first time, Syrian state television said.
NATO member Turkey accuses Russia of violating its airspace at least twice over the weekend, and has warned it will activate its rules of military engagement if such intrusions are repeated.
NATO has criticised the violations as "irresponsible" and urged Moscow to end raids against civilians and Syria's opposition forces.
On Tuesday, it stepped up the rhetoric, insisting the violations were intentional.
"For us, this does not look like an accident, it is a serious violation," NATO chief Jens Stoltenberg said at a press conference in Brussels.
"The violations were for a long time compared to previous violations of airspace we have seen elsewhere in Europe," he said.
Turkey meanwhile said it had summoned the Russian ambassador to Ankara for the second time in as many days to protest a violation of its airspace on Sunday.
Turkey warned that "Russia would be held responsible" for future intrusions, a Turkish official said.
Meanwhile, United Nations chief Ban Ki-moon urged Iran on Monday to pressure its ally Syria to reach a peaceful resolution of the brutal civil war there. During a meeting with Iranian Foreign Minister Javad Zarif, Ban "reiterated that there is no military solution to the conflict and asked Iran to exercise its influence in promoting a political solution," his office said. ?AFP