(CNN) -- A Ukrainian transport plane was shot down Monday by a rocket that Kiev's government contends appeared to be coming from Russia.
The plane was about four miles high over eastern Ukraine's Luhansk region near the Russian border, where the Ukrainian military has been battling pro-Russian separatists, officials said.
Crew members of the Antonov-26 made contact with the army, officials said, and the Ukrainian military is trying to bring them into territory it controls.
The plane's altitude was too high to be fired upon from the ground with a portable missile system, a statement from Ukrainian President Petro Poroshenko said.
The plane was hit with "a more powerful missile weapon that was probably used from the territory of the Russian Federation," the statement said.
A spokeswoman with the Russian President's office said she could not confirm any missile had been fired from the Russian Federation.
On Friday, pro-Russian separatists fired rockets at a Ukrainian military camp in the Luhansk region, killing 19 troops and injuring at least 55 others, according to Ukraine's counterterrorism office.
CNN's Elwyn Lopez contributed to this report.