NATO placed its fighter aircraft on high alert after a Russian missile reportedly entered Polish airspace and exploded inside the country.
According to international media reports, the missile entered Polish territory on Thursday morning during a wave of overnight ballistic missile and drone attacks launched by Russia against Ukraine.
The attacks reportedly killed at least eight people, including children, and injured more than 50 others.
A NATO spokesperson said that once the missile was detected, Poland and its allies immediately deployed F-16 fighter jets, aerial refuelling aircraft and airborne early warning planes.
The spokesperson added that the alliance would continue taking all necessary measures to protect the territory and security of its member states.
Polish authorities said the explosion in the eastern village of Tarnawa-Kolonia left a large crater but caused no casualties or material damage.
Analysts believe the incident could further increase tensions between Russia and NATO, while concerns continue to grow that the conflict in Ukraine could spread to other parts of Europe.
Russia has not yet issued an official statement regarding the incident.
