Poland has summoned the Russian ambassador and delivered a formal protest after confirming that a missile which landed in the eastern village of Tarnawa Kolonia in the Lublin region was a Russian Kh-101 missile.
The projectile came down on Thursday, and Polish authorities said no casualties or injuries were reported.
Prime Minister Donald Tusk announced on Friday that the ambassador had been summoned following the confirmation of the missile's origin.
The incident is the latest in a series of airspace incursions along NATO's eastern flank, raising concerns that the war in Ukraine could increasingly affect neighboring alliance members.
Poland's Ministry of Foreign Affairs said the Russian ambassador was informed of Warsaw's condemnation of the incident during Friday's meeting.
"The ambassador was informed of our unequivocal condemnation of hostile actions directed against the security of a sovereign state and its citizens," ministry spokesman Maciej Wewior told reporters.
Poland also demanded an end to actions that endanger civilian safety and warned that any escalation along the borders of the European Union and NATO was unacceptable.
The Russian embassy in Warsaw did not immediately respond to a request for comment.
Polish officials said the missile was part of an attack that killed at least eight civilians in Ukraine and injured more than 50.
Polish authorities said their investigation determined that the projectile was a Russian Kh-101 cruise missile produced near Moscow during the second quarter of this year.
Defence Minister Wladyslaw Kosiniak-Kamysz said the findings indicate Russia is employing recently manufactured missiles in its campaign against Ukraine.
He said the conclusion supports assessments that Russia's wartime missile stockpiles have been depleted.
Officials in Lublin said a Ukrainian expert who examined the wreckage identified the missile without doubt, while Wewior noted that the Kh-101 is used exclusively by Russian strategic aviation.
The incident adds to repeated missile and drone incursions involving Poland, Romania and the Baltic states, developments that have intensified concerns over the potential spillover of the conflict beyond Ukraine.