Ukraine-Russia Breaking News: Putin's Helicopters Attack Airfield, Cities Count Casualties

  BY MATT CANNON AND YEVGENY KUKLYCHEV   Russian President Vladimir Putin declared a "special military operation" underway in Ukraine on Thursday Putin said he was helping Russian-backed separatist enclaves in eastern Ukraine—Western leaders predicted this would be his pretext for invasion Explosions have rocked Ukraine's capital, Kyiv, and second-largest city, Kharkiv Russian troops have landed in Odessa, crossing the border into Ukraine, Ukraine's Interior Ministry said. "The invasion has begun," it warned.