Calls for end to "massacre" and urges nations to to take in refugees Russia"s invasion has forced more than 2.5 million people to flee Ukraine ROME: Pope Francis on Sunday issued his toughest condemnation yet of the Russian invasion of Ukraine, saying the “unacceptable armed aggression” and “massacre” must stop. “Faced with the barbarity of killing of children, of innocents and unarmed civilians, no strategic reasons can hold up,” he told 25,000 people in St. Peter’s Square during his Sunday blessing. Moscow says its action is designed not to occupy territory but to demilitarize its neighbor. It has also denied targeting civilian areas. “The only thing to do is stop this unacceptable armed aggression before it reduces cities into cemeteries,” Pope Francis said. “In the name of God I ask you: Stop this massacre!” Pope Francis said, before asking the crowd to join him in silent prayer for an end to the war. He called Ukraine’s besieged port of Mariupol a “martyred city” and again appealed for “truly secure humanitarian corridors” to allow residents to evacuate. Now in its third week, Russia"s invasion has forced more than 2.5 million people to flee Ukraine. The UN has recorded at least 596 civilian deaths, though it believes the true toll is much higher, and Ukraine’s Prosecutor General’s office said that at least 85 children are among them. Pope Francis also urged people to take in refugees from Ukraine and thanked those who had joined a “great network of solidarity” to help those fleeing war. The pope’s appeal came as Russia said it had attacked the Yavoriv training facility in western Ukraine. Ukrainian officials said at least 35 people were killed and 134 wounded Sunday when more than 30 cruise missiles were fired at the Yavoriv military range, just 25 kilometers (15 miles) from the Polish border. Poland is also a transit route for Western military aid to Ukraine, and the strikes followed Moscow’s threats to target those shipments. The training base appears to be the most westward target struck so far in the 18-day invasion. The facility, also known as the International Peacekeeping and Security Center, has long been used to train Ukrainian military personnel, often with instructors from the United States and other NATO countries. The base has also hosted international NATO drills. As such, the site symbolizes what has long been a Russian complaint: That the NATO alliance of 30 member countries is moving ever closer to Russia’s borders. Russia has demanded that Ukraine drop its ambitions to join NATO. The US issued a swift warning after the attack. White House national security adviser Jake Sullivan said on CBS News’ “Face the Nation” that Russia will face a response from NATO should any of its attacks in Ukraine cross borders and hit members of the security alliance — even by accident. Russian airstrikes also again hit the airport in Ivano-Frankivsk, another city in western Ukraine south of Lviv and 250 kilometers (155 miles) away from Ukraine’s border with NATO members Slovakia and Hungary. The city’s mayor, Ruslan Martsinkiv, said Russia’s goal was “to sow panic and fear.” Since their invasion more than two weeks ago, Russian forces have struggled in their advance across Ukraine, in the face of stiffer than expected resistance, bolstered by Western weapons support. Instead, Russian forces have besieged several cities and pummeled them with strikes, hitting two dozen medical facilities and leading to a series of humanitarian crises.