Ex-president Dmitry Medvedev, deputy head of Russia’s security council, said on Twitter that the incident “proves just one thing: waging a hybrid war against Russia, the West moves closer to the world war.”

Poland is protected by NATO’s commitment to collective defense — enshrined in Article 5 of its founding treaty — but the alliance’s response will likely be heavily influenced by whether the incident was accidental or intentional.

Warsaw has said it may invoke Article 4 of the treaty under which any member can call urgent talks when it feels its “territorial integrity, political independence or security” are at risk.

– ‘Consequence of Russia’s actions’ –

Russia invaded Ukraine on February 24 and still holds swathes of territory despite a series of recent battlefield defeats.

The conflict has caused deep unease in neighboring Poland where memories of Soviet domination are still very raw.

Poland shares a 530-kilometre (329-mile) border with Ukraine and has taken a lead in providing military and humanitarian aid to Ukraine and sanctioning Russia.

Despite the likelihood a Ukrainian missile was involved, the Polish government was clear it still held Russia responsible.

Polish Deputy Foreign Minister Pawel Jablonski told RMF radio that “in all likelihood, we are dealing with a consequence of Russia’s actions.”

He also responded to criticism of Poland’s own air defenses.

“Missile defense systems around the world are never one hundred percent effective systems that protect each millimeter of every country’s territory,” he said.

Ukrainian Foreign Minister Dmytro Kuleba had on Tuesday rejected as a “conspiracy theory” the idea that it may have been a Ukrainian missile.

– ‘Slap in the face’ of G20 –

President Volodymyr Zelensky sent “condolences over the death of Polish citizens from Russian missile terror”.

The explosion came after a wave of Russian missiles hit cities across Ukraine on Tuesday, including Lviv, near the border with Poland.

Zelensky said the strikes cut power to some 10 million people, though it was later restored to eight million of them, and also triggered automatic shutdowns at two nuclear power plants.

He said Russia had fired 85 missiles at energy facilities across the country, condemning the strikes as an “act of genocide” and a “cynical slap in the face” of the G20.

Source: Agence France Presse