The United States confirmed on Friday reports that a convoy of armoured vehicles including three T-64 Russian tanks moved into Ukraine from Russia and are now in the hands of the rebels.
US State Department deputy spokeswoman Marie Harf said the US had information that Russia has accumulated tanks of a type no longer used by its own forces at a site in southwest Russia, and some had recently left that spot.
"In the last three days, a convoy of three T-64 tanks, several BM-21 or Grad multiple rocket launchers, and other military vehicles crossed from Russia into Ukraine near the Ukrainian town of Snizhne.
This is unacceptable," Harf told reporters in Washington. She said that the department was confident that the tanks came from Russia. Internet videos later showed tanks of the same make moving through several cities in eastern Ukraine. The statement came after Ukrainian troops and pro-Russia separatists clashed earlier on Friday in Mariupol, a southern port town in eastern Ukraine. Also Friday, rebel leaders confirmed they had obtained three tanks.
Russia has not commented on the tanks, but its border guard service said two Ukrainian armoured vehicles crossed the border in the opposite direction Friday, into Russian territory near the southern city of Rostov-on-Don.
Russian news agencies quoted a spokesman for the border guard service as saying that the Ukrainian troops were able to return to Ukraine but left behind one of the vehicles after it apparently broke down. NATO condemned the reports of Russian tanks.