US concerned over separatists' advanced weapons in Ukraine
The US has expressed concern that pro-Russian separatists in Ukraine were using advanced weapons "from the outside" after they shot down an army helicopter killing 12 soldiers.
"We are disturbed by the ongoing violence in eastern Ukraine, including reports that separatists have shot down a Ukrainian military helicopter," White House Spokesman Jay Carney said.
"Now we cannot yet verify the details of these reports, but we are concerned that this indicates separatists continue to have access to advanced weaponry and other assistance from the outside," he added.
The Mi-8 helicopter gunship was shot down with a sophisticated surface-to-air missile.
Among the dead was a Ukrainian general.
Moscow has consistently denied accusations of providing assistance to the pro-Russia separatists.
Acting President of Ukraine Oleksandr Turchynov said the weapon used was a Russian man-portable air defense system.