Washington - A Malaysian airliner with 298 people on board was shot down over Ukraine by a surface-to-air missile on Thursday but it was unclear who fired the weapon, US officials told AFP.
Intelligence analysts are reviewing data to determine whether the weapon was launched by pro-Moscow separatists in Ukraine, Russian troops across the border or Ukrainian government forces, said two US officials, who spoke on condition of anonymity.
"We are working through all the analysis," said one official.
But that there was little doubt that the plane was struck by a surface-to-air missile, the official said.
"That's what we strongly believe."
In Detroit, US Vice President Joe Biden said the plane was "apparently... and I say apparently because we don't have all the details yet... shot down. Not an accident. Blown out of the sky."
However, Biden cautioned that the US was still seeking details about the cause of the crash and reports that there were American citizens aboard the plane.
The airliner was reportedly flying at an altitude of more than 30 000 feet, putting it within range of Russian-made Buk missiles that are in the arsenals of both Ukrainian and Russian forces.
Malaysian Airlines flight MH17 took off from Amsterdam en route to Kuala Lumpur. Ukrainian air traffic controllers lost contact with the plane at 14:15 GMT, about four hours into its flight and about 50km from the Russia-Ukraine border.