Russian military units moving in a convoy formation with self-propelled artillery in Ukraine, in this satellite image captured on Aug. 21 and released by NATO. Digital Globe

MOSCOW - Russian Foreign Minister Sergei Lavrov claimed Friday that NATO satellite pictures showing Russian military involvement in Ukraine had "turned out to be from computer games." Speaking on Russia 24 television, Lavrov said that the West had produced "no facts" to support its accusations that separatists in eastern Ukraine had been joined by Russian forces.

On Thursday, NATO released images it said showed that Russian combat troops had crossed into Ukraine. The images, some taken as recently as Aug. 21, purportedly depict Russian self-propelled artillery units moving in a convoy through Ukraine and then establishing "firing positions" in Krasnodon, just outside the Russian border. On Friday, NATO Secretary-General Anders Fogh Rasmussen said Russian troops are involved in "direct military operations" inside its smaller neighbor.

IN-DEPTH

- F. Brinley Bruton and Albina Kovalyova