Russian-backed rebels in eastern Ukraine are preparing for something big (Source Reuters) The United States on Wednesday accused Russia of building up air defense systems inside eastern Ukraine and of involvement in training exercises of pro-Russian rebels in breach of a European-brokered truce.

“This is the highest amount of Russian air defense equipment in eastern Ukraine since August,” State Department spokeswoman Marie Harf said in a statement. She said the increasingly complex nature of the training exercises “leaves no doubt that Russia is involved.” “The training has also incorporated Russian UAV’s (unmanned aerial vehicles), an unmistakable sign of Russian presence,” Harf added. Fighting has picked up in eastern Ukraine in recent weeks despite the ceasefire agreed upon in February, with each side accusing the other of violence. Russian Foreign Minister Sergei Lavrov said on Monday he believed a surge in ceasefire violations had, however, passed. But Harf said Russia was building up its forces along the Ukrainian border.

“After maintaining a relatively steady presence along the border, Russia is sending additional units there,” she said, adding that the increase marked the largest presence of Russian troops on the border since October.