US Secretary of State Marco Rubio on Saturday called the incursion of Russian-made drones into Polish airspace during an attack on Ukraine earlier this week an "unfortunate and dangerous development."

"The question is whether the drones were targeted to go into Poland specifically. If that's the case, if the evidence leads us there, then obviously it would be... highly escalatory," Rubio told reporters in Washington DC.

US President Donald Trump said Thursday the alleged incursion of Russian drones into Poland may have happened by "mistake," even as the incident alarmed Europe.

Polish Prime Minister Donald Tusk dismissed Trump's suggestion.

"We would also wish that the drone attack on Poland was a mistake. But it wasn't. And we know it," Tusk said Friday on X.

Polish authorities said they had recovered parts of 17 Russian-made drones, which fell without causing any injuries or major damage in the east of the country Wednesday.

Russia, which has rebuffed Trump's pleas for a ceasefire in Ukraine, apparently fired the 17 drones that landed in Poland -- whose security is guaranteed by the US-backed Nato alliance and whose president visited the White House the previous week.

European capitals and the European Union labelled the raid a test of the resolve of the Nato alliance in the face of Russia's ongoing conflict with Ukraine.

Separately, Romania's defence ministry said on Saturday that the country's airspace was breached by a drone during a Russian attack on infrastructure in neighbouring Ukraine.

After the Nato member scrambled two F-16 fighter jets late on Saturday to monitor the situation, the aircraft "detected a drone in national airspace" and tracked it until "it disappeared from the radar" near the village of Chilia Veche, said a ministry statement. (AFP)