(QHA) -

East Ukraine separatists likely used weapons supplied by Moscow to shoot down Ukrainian aircraft in recent weeks, NATO's top commander General Philip Breedlove said on Monday, AFP reports.

Russia was maintaining a large troop presence near Ukraine's border and had provided anti-aircraft weapons and other hardware to the rebels, Breedlove told a Pentagon news conference.

Asked if the separatists used the weapons to take out Ukrainian aircraft in recent weeks, Breedlove said all the facts need to be "sorted out" but "I would say it's a very good likelihood" that Russian-supplied arms were behind the attacks.

"What we see in training on the east side of the (Ukrainian) border, is big equipment, APCs (armored personnel carriers), anti-aircraft capability . . .and now we see those capabilities being used on the west side of the border," the general said.

A Ukrainian military cargo plane was shot down on June 14, killing 49 people on board, and a Ukrainian helicopter was downed last week, leaving nine troops dead. Officials in Kiev blamed pro-Russian separatists for both incidents.