WASHINGTON - The United States believes Moscow provided Ukrainian rebels with the missile launchers that downed Malaysia Airlines Flight MH17, and moved them back into Russia after it was hit, US newspapers reported late Saturday.
A US official speaking on condition of anonymity told the Washington Post intelligence services were "starting to get indications... a little more than a week ago" that three Russian launchers had been moved into Ukraine.
The Post said Vitaly Nayda, Ukraine's counterintelligence chief, had photographs and related evidence that three Buk M-1 antiaircraft missile systems moved from rebel-held territory into Russia early Friday, less than 12 hours after the plane was downed.
"We do believe they were trying to move back into Russia at least three Buk [missile launch] systems," the US official told the Post.
Kiev has accused the pro-Moscow militias of using a Russian-supplied Buk system to down the jet after confusing it with a Ukrainian military transporter.
According to Nayda, two antiaircraft systems were spotted entering Russia at 2 am Friday, one with its full complement of four missiles but the other apparently missing a missile.
Two hours later, at 4 am, Nayda said a convoy of vehicles that included one of the launchers crossed into Russia.
The Buk systems, also known as the SA-11 Gadfly, are self-propelled tracked vehicles that carry surface to air missiles.
US President Barack Obama and major world leaders believe the Malaysia Airlines jet was blown out of the sky at 33,000 feet (10,000 metres) by a sophisticated surface-to-air missile fired from rebel-controlled territory.
The attack killed all 298 people on board.
Ukraine accuses Russia of helping the militias to hide and destroy key evidence that could prove their alleged involvement.
"The assumption is they're trying to remove evidence of what they did," an unnamed senior US official told The Wall Street Journal.
The WSJ also quoted the official as saying new US intelligence assessments indicate Moscow likely provided pro-Russia separatists with sophisticated antiaircraft systems in recent days, matching the evidence put forward by Ukraine.
Russian President Vladimir Putin rejects all charges of providing funding or military support to the pro-Russian insurgents, and blames Ukrainian authorities for the tragedy.
Rebel commanders have also denied being in possession of any functioning Buk systems.