Poland has closed four airports, and Polish and NATO aircraft have also been emergencyly launched after reports of Russian unmanned aerial vehicles (UAVs) in the country's airspace.
The Polish Army's combat command said in a statement: "Crustom air defense and radar reconnaissance systems have reached the highest alert level" after Russia launched large-scale airstrikes on Ukrainian territory.
"To ensure the security of Polish airspace, the Combat Command of the Polish Armed Forces has activated all necessary processes," the statement said, stressing that the Polish army "is fully ready for immediate response".
A pilot notice posted on the US Federal Aviation Administration's website said that Poland had closed four airports on the night of September 9, including the country's largest Chopin airport in Warsaw, "due to unplanned military operations related to national security."
The Ukrainian air force had previously reported on the messaging app Telegram that the drone was heading west and threatening the city of Zamosc in Poland, but the statement was later deleted.
It is not yet clear how many drones are operating in Polish airspace. However, Ukrainian media reported that at least one drone was heading towards the city of Rzeszow, western Poland.
