Russian helicopters allegedly violated Polish airspace last week, according to a Polish publication. The incident occurred near the exclave of Kaliningrad on the Baltic sea.
According to Gazeta Polska Codziennie, a Polish official saw the helicopters, flying in formation, flew across the border, but returned after several minutes.
The Polish government has not yet commented.
Read more: Russia puts spy behind bars for 13 years
Earlier, the government condemned Russia for “aggressive manoeuvres” over the Baltic Sea. A Russian jet barrel-rolled a U.S. reconnaissance plane, according to the U.S. military. Previously, Russian bombers had performed a move against a U.S. warship, heightening tensions in the area.
Russia has also been conduction incursions near U.K. airspace, as NATO-Russia tensions are at heights not seen since the end of the Cold War.
But other armed forces around the world have engaged in such behaviour in the past, known as probing, in order to test military responses.