Pro-Russian rebels in eastern Ukraine were seen advancing against government forces on Aug. 27, while more and more Western officials backed up Kiev's claims that Russian army units are operating inside the country.
Russia's War Against Ukraine
France 24: Ukraine calls on NATO amid Kremlin-backed rebel attack (VIDEO)
Pro-Russian militants listen to instructions near a machine gun during their service in eastern Ukrainian city of Donetsk on Aug. 8, 2014.
