The German government said on Tuesday that Russia was behind an attempted drone attack on a Ukrainian cargo plane at Leipzig/Halle Airport last month.
The Polish foreign ministry said in a statement that it firmly opposed "acts of sabotage and attempted hybrid attacks" in NATO and EU countries.
It added that Russia's actions would not weaken Poland's determination to support Ukraine in its fight against Russia's invasion.
"In response to reports confirming Russia's responsibility for the attempted attack at Leipzig Airport in August, Poland expresses its solidarity with Germany in opposing Moscow's terrorist activities," the statement said.
"We firmly oppose acts of sabotage and attempted hybrid attacks on the territory of NATO and EU member states," it added.
"It remains our priority to strengthen the eastern flank of the North Atlantic Alliance and the European Union and ensure the security of our citizens and infrastructure," the statement said.
"Russia's actions will not weaken our resolve to support Ukraine in its fight against the aggressor," it added.
"Poland will continue its efforts to ensure that Russia's terrorist activities are met with an appropriate response from NATO and the EU," the foreign ministry said.
"We are determined to see Russia subjected to new sanctions packages, particularly those aimed at limiting the capabilities of its defence and security apparatus," it added.
European Union foreign policy chief Kaja Kallas said on Wednesday that the Leipzig attack bore all the hallmarks of state-sponsored terrorism.
German police were on Wednesday investigating the latest suspected act of sabotage targeting the country's electricity grid, as authorities remained on high alert for attacks on critical infrastructure, according to news reports.
Officers said they were investigating an act of premeditated vandalism targeting power substation infrastructure near the western city of Bergheim at about 4 p.m. on Tuesday.
In a separate incident on Wednesday, an unknown object exploded near a train station in the southern city of Augsburg, German police said, adding that two passersby, aged 17 and 18, suffered minor injuries.
The blast occurred in a passageway of a station building, police said, adding that the injured individuals were Ukrainian nationals.
German news outlet Bild reported that a hand grenade exploded in front of a jewellery store and that the train station itself was apparently not the target.
A day earlier, devices containing conductive material damaged power lines at one of the most critical high-voltage nodes in the eastern state of Brandenburg, near the Polish border.
Brandenburg's interior minister, Jan Redmann, said there appeared to be parallels between the incidents but that the investigations were at an early stage, the Reuters news agency reported.
(gs)
Source: IAR/PAP, Reuters, gov.pl