Secretary of State John Kerry said on Sunday that evidence in the downing of a Malaysian jetliner points to pro-Russian separatists in Ukraine using a missile system that came from Russia.
"It's pretty clear that this is a system that was transferred from Russia," Kerry said in an interview on CNN.
Kerry cited a mix of U.S. intelligence and social media reports as evidence that he says "obviously points a very clear finger at the separatists."
He also said there's been a major flow of arms and weapons crossing the Russian border over the past month to help the Ukrainian rebels who are fighting to break away in the east from the central government.
Kerry said separatists have shot down about 12 aircraft over the last month, and bragged about Thursday's attack on the Malaysian plane until they realized it was a commercial jet.
U.S. intelligence officials believe Moscow likely gave the sophisticated antiaircraft systems to pro-Russia separatists in eastern Ukraine that brought down Malaysia Airlines Flight 17, killing all 298 people aboard, The Wall Street Journal reported Saturday night.
U.S. officials suspect that Russia smuggled SA-11 Gadfly surface-to-air missile systems into Ukraine with other military equipment, including tanks, the Journal said, adding that the systems were likely moved back to Russia after the passenger jet was shot down Thursday.
"The assumption is they're trying to remove evidence of what they did," the unidentified senior official told the Journal.
The U.S. intelligence information parallels claims of Ukrainian government officials, who have said the separatists had in their possession "at least" three Russian-made SA--11 systems.
Ukraine state security official Vitaliy Nayda said Saturday that as part of a cover-up of who fired the missile, three of the systems were transported back to Russia just hours after the plane was shot down. Nayda displayed photos which he said showed them on the road to the Russian border.
Moscow denies supplying separatists with heavy weapons, despite mounting evidence to the contrary put forward by U.S. officials. "We know there are Russian troops inside Ukraine," said U.S. official quoted by the Journal. "Russian troops, Russian equipment."
The downing of the aircraft has become a diplomatic flash point, with Russian President Vladimir Putin blaming Ukraine for the tragedy while European government leaders are urging him to force the insurgents to back down and allow unfettered access to the crash site.
The crash threatens to escalate five months of conflict in eastern Ukraine, sparked by Russia's annexation of Crimea.
The SA-11 Gadfly, known locally as the Buk-M, is a radar-guided weapon that can find a target at a range of 140 miles and reach altitudes as high as about 72,000 feet, according to the army- technology.com website.
U.S. Rep. Ed Royce, a California Republican who heads the House Foreign Affairs Committee, yesterday broached his suspicions of a cover-up.
"I think what's happened is a rather poorly trained separatist group here probably have inadvertently shot down an airliner and are now trying to cover this up," he said on CNN. "That's the part you see on the ground."