Separatist rebels in conflict-racked eastern Ukraine claimed responsibility for downing the Antonov-26, but Ukrainian officials swiftly ruled that out and blamed Russia instead.
There was no immediate comment from Russia about the plane.
In the last two weeks, the government has halved the territory in eastern Ukraine held by pro-Russia separatists, who have been forced back into the cities of Luhansk and Donetsk. Many in the armed insurgency are known to be Russian nationals, but Moscow says they are simply citizens who went to fight in Ukraine on their own.
Defense Minister Valeriy Heletey said the plane was flying at an altitude of about 21,300 feet, which he said was too high to be reached with the weapons used by the separatists. Rebels are known to have Igla portable surface-to-air missiles, which work up to about 11,500 feet.
Ukraine’s Security Council spokesman Andrei Lysenko said data from the plane’s surviving crew suggested the rocket was either a surface-to-air Pantsir missile or a missile fired by a plane from Russia’s Millerovo Air Force base.
In London, Charles Heyman, a defense analyst who edits a book called “Armed Forces of the European Union,” said the missile was more likely fired by the Ukrainian rebels.
“I doubt the transport plane was flying at 6,500 meters (21,350 feet). That doesn’t make sense. The higher you fly, the more it costs and the plane would have had to be pressurized,” Heyman said. “It was probably shot down using SAM-6 missiles owned by the rebels, which they have quite a few of.”
Fighting intensified around Luhansk, meanwhile, as government forces stepped up efforts to disrupt rebel lines and reclaim more territory.
The Defense Ministry said Monday that government troops had retaken several villages around Luhansk – including Metalist, Oleksandrivsk, Bile and Rozkishne – and had reopened a corridor to its civilian airport, suggesting the government’s plan to form a security cordon around Luhansk is yielding results.