Rebels have downed Ukrainian aircraft flying at high altitudes . A pro - Russian rebel commander set off anti - aircraft missiles . The border area with Russia is very porous , unguarded in many places . Some believe that larger weapons have come into Ukraine from Russia .
Rebels have downed Ukrainian planes flying at high altitudes . A pro-Russian rebel commander shows off anti-aircraft missiles . The border region with Russia is very porous , unguarded in many places . Some contend that larger weapons have come into Ukraine from Russia .