ANKARA, Turkey – Turkey said Saturday that a Russian warplane has again violated its airspace despite several warnings – two months after Turkey’s military shot down a Russian jet for crossing over its territory. The past incident seriously strained the previously close ties between the two countries, damaging a strong economic partnership.

A Foreign Ministry statement on Saturday said that a Russian SU-34 crossed into Turkish airspace on Friday, ignoring several warnings that were delivered both in Russian and in English by Turkish radar units. It said Ankara summoned the Russian ambassador to the ministry Friday evening to “strongly protest” the violation. The Turkish statement did not say where the infringement occurred.

“This violation is a concrete indication of Russian’s acts aiming to escalate problems, despite the clear warning by our country and by NATO,” the statement read. “We openly and clearly call on Russia to act responsibly so that the Turkish air space, which is a NATO airspace, is not violated.”

“We emphasize once again the fact that Russia will be held responsible for any dire consequences which can emerge from such irresponsible acts,” the statement said.

There was no immediate comment on the incident from Moscow.

In November Turkey shot down a Russian plane which violated its airspace near Syria, touching off a crisis between the two countries. It was the first time in more than half a century that a NATO nation had shot down a Russian plane.

Turkey shot down the Russian Su-24 bomber near the border with Syria on Nov. 24, saying it violated its airspace for 17 seconds despite repeated warnings. Russia insists the plane never entered Turkish airspace. One pilot and a Russian marine of the rescue party were killed in the incident.

The Russian military quickly sent missile systems to Syria and warned that it would fend off any threat to its aircraft. Moscow also punished Turkey by imposing an array of economic sanctions.