At least three Russian drones were shot down by Nato and Polish aircraft in Poland's airspace during overnight attacks on Ukraine, the Polish prime minister has said.

Donald Tusk told MPs that Poland had recorded 19 drone incursions, with some flying deep enough to temporarily close four airports, including Warsaw's main hub Chopin.

Jets were scrambled in response to what Tusk described as a "provocation".

The incident marks the first time Russian drones have been shot down over the territory of a Nato member since Moscow's full-scale invasion of Ukraine in 2022.

Russia declined to comment, while Ukraine's foreign minister said the incident showed "Putin continues to escalate, expands the war".

Kremlin spokesman Dmitry Peskov told reporters in Moscow: "We wouldn't like to comment on this. This is not for us to do so. It's the prerogative of the Defence Ministry [to answer]."

Russia's temporary charge d'affaires in Poland said Warsaw had not provided evidence that the drones were of Russian origin.

Polish authorities have no information suggesting anyone was injured or died "as a result of the Russian action", Tusk told Poland's Parliament.

"The fact that these drones, which posed a security threat, were shot down changes the political situation," he said.

"I have no reason to claim we're on the brink of war, but a line has been crossed, and it's incomparably more dangerous than before. This situation brings us the closest we have been to open conflict since World War Two".

Authorities in Poland have found seven drones and the remains of an unidentified object in sites across the country, an interior ministry spokeswoman has said.

Karolina Galecka told a news conference that five of the drones and the remains of the unidentified object were found in different locations in Lublin province in eastern Poland, bordering Belarus and Ukraine.

Two of the drones were discovered in central and northern Poland, much further from the borders, she said.

One was discovered in a field in Mniszków, in Łódź province in central Poland, about 250 km (155 miles) from the Belarusian border. Another was discovered near the city of Elbląg in northern Poland.

Tusk, who convened an emergency meeting on Wednesday morning, has asked to invoke article 4 of the Nato treaty, which formally starts urgent talks between members of the alliance.

Poland is a member state of Nato - which ties the US and many European nations together on collective defence.

Both Tusk and Polish President Karol Nawrocki have said they are in "regular contact" with Nato Secretary General Mark Rutte, who praised a "very successful reaction" by the alliance.

"The security of our homeland is our highest priority and requires close cooperation," President Nawrocki said on X.

Rutte added that the situation is being investigated, as he condemned Russia's "reckless behaviour", irrespective of whether it was deliberate.

Belarus, a close Russian ally, claimed the drones entered Polish airspace accidentally after their navigation systems were jammed.

Overnight, the Operational Command of the Polish Armed Forces said the drones were tracked by radar by both Polish and Nato aircraft stationed in the country.

The military said: "As a result of the attack by the Russian Federation on Ukrainian territory, there was an unprecedented violation of Polish airspace by drone-type objects.

"Searches and efforts to locate the potential crash sites of these objects are ongoing."

Although Poland's military operation has ended, it urged people to stay at home, naming Podlaskie, Mazowieckie, and Lublin regions as most at risk.

"With the safety of citizens in mind, we urge that in the event of observing an unknown object or its debris, do not approach, touch, or move it," the military wrote on X.

"Such elements may pose a threat and contain hazardous materials. They must be thoroughly inspected by the appropriate services."

The Polish military also thanked Nato's Air Command and the Netherlands for deploying F35 fighter jets.

Flight operations were suspended for hours at Warsaw's Chopin and Modlin airports, as well as at Rzeszów–Jasionka and Lublin.

A number of flights which had been due to land at Chopin airport were diverted to Gdansk, Katowice, Wroclaw, Poznan and Copenhagen.

After airspace over the the capital was re-opened, Chopin airport said disruptions and delays may last throughout the day and warned passengers to expect delays.

The Russian drones that entered Poland were part of the latest major aerial attack on Ukraine.

In total, Ukraine's air force reported more than 400 drones and 42 cruise missiles were launched just before midnight and the bombardment lasted throughout the night.

President Volodymyr Zelensky warned the latest attack was "an extremely dangerous precedent for Europe".

Writing on Telegram, Ukraine's Foreign Minister Andrii Sybiha said Putin is "testing the West".

"The longer he faces no strength in response, the more aggressive he gets.

"A weak response now will provoke Russia even more -- and then Russian missiles and drones will fly even further into Europe."