An unidentified aerial object entered the airspace of NATO-member Poland from the direction of Ukraine on Friday, Polish officials said, as Russia conducted one of its biggest attacks overnight in Ukraine since the launch of its invasion.

"In the morning, an unidentified aerial object entered the airspace ... and from the moment it crossed the border until the signal disappeared, it was observed by the radars of the country's air defense system," the Operational Command said on social media platform X.

"In accordance with applicable procedures, the operational commander of the armed forces mobilized the available forces and resources at his disposal."

Private broadcaster TV Republika had reported that a search for the object was happening near the town of Hrubieszow in southern Poland. Reuters was unable to immediately confirm this information.

"We received information that an object appeared on the radar near Hrubieszow," Krzysztof Komorski, governor of the Lublin region said on X. "We have no confirmation that it fell within our region."

Russia targeted Ukraine with 158 drones and missiles overnight, aiming for critical infrastructure, industry and military facilities, the Ukrainian military said.

A stray Ukrainian missile struck the Polish village of Przewodow in southern Poland in November 2022 in an incident that raised fears of the war in Ukraine spilling over the border.

In April, a military object was found in a forest close to the village of Zamosc near the northern city of Bydgoszcz. It was later reported to be a Russian missile.

Polish officials said emergency services, including police and volunteer army units, were scouring the area but it was unclear whether the object had landed on Polish territory. There were no reports of casualties.

Prime Minister Donald Tusk was due to meet with army and security services chiefs around midday local time (1100 GMT).