Polish jets intercepted a Russian aircraft on Tuesday that was flying a reconnaissance mission in international airspace over the Baltic Sea without a filed flight plan and with its transponder turned off, the Polish army said on Wednesday.

Axar.az informs, citing Reuters, countries on NATO’s eastern flank have been on high alert for potential airspace incursions since September when three Russian military jets violated Estonia’s airspace for 12 minutes just days after more than 20 Russian drones had entered Polish airspace.

“Polish fighter jets intercepted an Il-20 aircraft conducting a reconnaissance mission in international airspace, without a filed flight plan and with its transponder turned off. The aircraft did not violate Polish airspace,” the Operational Command of the Polish Armed Forces said.