The Polish Foreign Ministry said the two people died in the village of Przewodów after the rocket struck at 3:40 p.m. local time on Tuesday. Photos posted on social media showed a damaged farm vehicle lying on its side next to a large crater. Local media reported that the victims were farm workers. Poland’s president and prime minister did not confirm the missile was fired by Russia during a late-night press conference in which both appeared to avoid statements that could escalate tensions with Moscow. “There is no conclusive evidence as to who fired the missile,” President Andrzej Duda said after an emergency security meeting of the Polish government. Duda also referred to the missile attack as “a one-time incident”. If Poland’s investigation confirms that the missile was fired by Russia, it would be the first strike on a NATO country since Russia launched a full-scale invasion of Ukraine on February 24. Poland will discuss the missile attack with its NATO allies on Wednesday. Duda said Poland would “most likely” trigger Article 4 of the NATO treaty, which deals with discussions about a potential threat to a member of the alliance, before considering Article 5, which would require other NATO members to defend the NATO. Russia’s defense ministry denied responsibility, adding that the missile fired by its forces was a “deliberate provocation aimed at escalating the situation”. Poland’s foreign minister summoned the Russian ambassador for “immediate detailed explanations,” while Poland’s UN representative tweeted that he would raise the matter with the Security Council. The White House said President Joe Biden, who is in Bali, Indonesia, for the G20 summit, was “briefed on the reports from Poland” and spoke with Duda. However, both the Pentagon and the US National Security Council said they could not confirm Russia’s claims of being behind the strike. Biden offered “full US support and assistance for the Polish investigation” and reaffirmed Washington’s “ironclad commitment to NATO,” according to the White House. The US president, along with the leaders of the United Kingdom, France, Germany, Canada, Japan, Spain, Italy and the Netherlands, as well as the presidents of the European Council and the European Commission, met for an emergency meeting in Bali on Wednesday morning. a person who was present told the Financial Times. The explosion in eastern Poland came amid a Russian barrage of missiles fired at Ukrainian cities that damaged energy infrastructure as well as urban buildings. Ukrainian officials, including President Volodymyr Zelenskyy, were quick to blame Russia for the Polish strike, though they offered no concrete evidence to back up the claims. “Russian missiles hit Poland,” Zelensky said in a videotaped speech on Tuesday night, adding that Moscow had fired 90 missiles aimed at Ukraine. After speaking with Duda, Zelensky tweeted that “Ukraine, Poland, all of Europe and the world must be fully protected from terrorist Russia.” Leaders of several NATO countries in Central and Eastern Europe warned that the strike would mark a major escalation of the conflict if the Polish investigation proves the Kremlin was behind the attack. Recommended Two NATO officials told the FT that the situation had caused concern but not panic within the alliance. Polish Prime Minister Mateusz Morawiecki said Warsaw would “increase the readiness of selected units of the Polish armed forces with a special emphasis on airspace surveillance” and with the help of the country’s allies. Duda said “all the leaders I spoke to today absolutely assured me of alliance support,” adding that “we will look at this issue together.” Artis Pabrix, Latvia’s defense minister, tweeted that Article 4 was “in effect”. In a further sign of the conflict’s potential spillover, Moldova reported on Tuesday that it had lost electricity following missile attacks in Ukraine, as a power line connecting the two countries was automatically disconnected. Oleksii Reznikov, Ukraine’s defense minister, called on the West to provide further air defense systems to protect the country from Russian strikes. Additional reporting by James Politi in Washington and Henry Foy in Bali