From a Ukrainian news report here:
Convoy of three tanks and two KAMAZ trucks under the flags of Russia popped Makeevki in Donetsk. Video shot in Makeyevka. According to eyewitnesses, the tanks are now in the territory of Donetsk, according to “News of Donbass.”
Fact movement of Russian tanks in the direction of Donetsk confirms military expert Dmitry Tymchuk. “Across the border from Russia to Ukraine invade not only trucks and armored vehicles, but also tanks. Recent data: column, which included tanks from Russia, goes to Donetsk” – he said. According to experts, Russia is not even trying to hide the fact that its military intervention in the Donbass: “The Kremlin takes off his mask. If anyone has any doubt that this is a blatant invasion of Russia, I would like to see this person. interesting to see what it looks like the embodiment of naivete.”
However, note that the Ukrainians have good reason to lie about Russian troops entering the country in order to portray Russians as bad guys. A spokesman for the Russian government said reports of Russian forces entering the Ukraine were nonsense.
The tanks in this video are T-64′s, and the video was supposedly taken inside the city of Donetsk today. One of the armored vehicles in this column is flying the Russian flag. Note the locals cheering the arrival of these troops. However, three T-64′s were captured by the rebels the other day in Donetsk. So are these just tanks that were seized by the rebels, who then decided to put a Russian flag on them? Why would they do that? The rebels fly the rebel flag, not the Russian flag.
Weighing the evidence, it appears that the Ukrainians are right and a small armored column of Russian forces has indeed crossed the border and moved into the Donbass. However, we will not know for sure until we get some sort of official confirmation.