How Countries Are Responding to the Explosion in Poland

An explosion in Poland near the border with Ukraine on Tuesday sparked immediate and conflicting explanations from governments grappling with the potential for Russia’s war in Ukraine to spill over into a broader conflict.

Here is a look at what nations involved are saying:

Poland

President Andrzej Duda said the cause of the explosion was “most likely a Russian-made missile” but that it was still under investigation. Mr. Duda said it was “highly likely” that he would invoke Article 4 of the NATO charter, under which members confer when a nation’s territorial integrity or security has been threatened.

Zbigniew Rau, Poland’s foreign minister, summoned Russia’s ambassador to demand “immediate detailed explanations” for the blast, according to a statement from the ministry.

Russia

Russia’s Defense Ministry denied involvement. On Telegram, the ministry wrote that any statements by Polish officials or media outlets about Russian missiles hitting the village were a “deliberate provocation.” Russia launched a widespread missile attack on Ukraine on Tuesday, with roughly 90 missiles aimed primarily at the country’s electrical infrastructure.

“No strikes on targets near the Ukrainian-Polish state border were made,” the ministry said, although Ukrainian reports disputed that account.

Ukraine

The explosion’s proximity to the border — about four miles — has raised the possibility that it was caused by the remains of a missile shot down by Ukraine’s air defense systems, or by a Ukrainian air defense missile. Both Russia and Ukraine are believed to use Russian-made missiles.

Ukraine’s foreign minister, Dmytro Kuleba, said in a Twitter post that the explosion in Poland was not caused by a Ukrainian air defense missile.

Ukraine’s president, Volodymyr Zelensky, was seized on the possibility of Russian involvement and called it evidence of “a very significant escalation.” He alluded to Poland’s membership in NATO by saying Russia had waged an “attack on collective security.”

United States

Speaking on the sidelines of the Group of 20 meeting in Indonesia, President Biden said that “preliminary information” indicated the missile had not been fired from Russia, without addressing whether it could have been launched by Russian troops in Ukraine or from the Black Sea. In response to a reporter’s question, he said, “I don’t want to say that until we completely investigate,” but “the trajectory” of the missile made it unlikely “that it was fired from Russia.”