New satellite imagery from Maxar shows a substantial increase in the deployment of Russian helicopter forces close to the Ukrainian border.
Maxar assessed that a new helicopter unit and battle group deployment consisting of tanks, armored personnel carriers and support equipment have deployed to Millerovo airfield, situated 16 kilometers from the border with Ukraine.
Millerovo is close to the part of Ukraine's border that is controlled by pro-Russian separatists of the self-declared Luhansk People's Republic.
Slightly further north, Maxar said that a new helicopter unit (more than 20 helicopters) has deployed near Valuyki, approximately 27 kilometers east of the border with Ukraine.
As seen in a previous imagery package, nearly 20 helicopters remain deployed near Belgorod, approximately 35 kilometers east of the border with Ukraine.
Videos uploaded to social media, and vetted by CNN, show that attack helicopters are present at both airfields near Valuyski and Belgorod, Russia.
In Crimea, there are now 70 helicopters, more than 60 were first observed earlier this week, at a disused airbase at Lake Donuzlav on the Black Sea coast remain in place.
The increase comes despite a statement earlier this week from the Russian Ministry of Defense saying that some military units would be moved away from Ukraine and return to their home bases. Russia even published videos of trains moving a number of tanks as evidence that it was following through on its statement.
In the past week a combination of satellite imagery and social media videos have shown advanced Russian tanks, howitzers and ballistic missiles moving towards the Ukrainian border, especially to the north and north-east.
And satellite imagery earlier this week showed troops, military vehicles and helicopters at the Zyabrovka airfield near the city of Gomel in Belarus, around 25 kilometers from the Ukrainian border.