WARSAW - Poland put its military on high alert Wednesday after what the country’s president said was “most probably” a strike by a Russian-made missile. Western leaders were scrambling to respond to the potential major escalation of the war in Ukraine, with an “emergency roundtable” due to be held Wednesday on the sidelines of the G20 summit in Indonesia. Warsaw said the missile killed two people in the village of Przewodow but did not have conclusive evidence of who fired it, adding that Moscow’s ambassador has been summoned to provide “immediate detailed explanations”. Poland put its military on heightened alert after an emergency national security council meeting. “There has been a decision to raise the state of readiness of some combat units and other uniformed services,” spokesman Piotr Muller told reporters after the meeting in Warsaw, adding that “our services are on the ground at the moment working out what happened.”