Poland's border authority said on Sunday that one of its aircraft had been intercepted by a Russian jet that performed dangerous aerial maneuvers in close proximity to its plane.

Poland's Border Guard said one of its planes was conducting patrols over the Black Sea for EU border protection agency Frontex on Friday when the incident took place. 

What happened during the incident?

A Polish Turbolet L-410 was flying over the Black Sea area when a Russian Sukhoi Su-35 fighter jet "flew without any radio contact into the operational area designated by Romania, and then performed aggressive and dangerous maneuvers," the border authority said in a statement.

The Russian aircraft allegedly made three approaches toward the Polish plane, and the resulting turbulence caused the crew of five Polish border guards to lose control of the plane and lose altitude.

"The Russian warplane flew right in front of the nose of the SG plane, crossing its flight path at a dangerous distance," the statement said.

It added, citing the crew's assessment, that the distance was about 5 meters (around 16 feet), after which the Russian aircraft then moved away.

The Polish aircraft managed to land safely in Romania afterward.

Romania condemns Russian behavior

On Saturday evening Romania's Ministry of National Defense — which had been first to report the incident — condemned the Russian plane's "aggressive and dangerous" behavior.

Bucharest said that the Polish aircraft had been conducting a routine Frontex patrol in conjunction with Romania's border police on Friday when the incident is said to have happened.

"This incident is further evidence of the provocative approach of the Russian Federation in the Black Sea," said Bucharest, adding that the behavior of the Russian aircraft was "totally unacceptable."

Romanian and Spanish aircraft were placed on "pre-alert" by NATO when the incident occurred, but intervention was not necessary, the Romanian statement said.

In March, a Russian fighter jet allegedly forced down a US military "Reaper" surveillance drone over the Black Sea. The US military said the Russian aircraft dumped fuel on the American drone and then collided with it.

Moscow denies this happened and said the drone crashed of its own accord.

kb/wd (AFP, dpa)