>> reporter: well, russia has been pretty tight-lipped on the issue of the downing of the transport plane. there have been a lot of accusations circling between moscow and kiev -- kiev and moscow, rather, the past couple days, in particular the deployment of russian tanks inside ukraine. the kremlin denied that's taken plague, but kiev says that moscow allowed three tanks to cross its border in support of the rebels. that's been backed by the state department in want. and nato, the western military alliance has within the past few hours put out some images, which it says supports the accusation as well. so if it's true, that could have serious consequence foss that relationship between moscow and the west. >> matthew chance, thanks so much. keep us posted. all right. coming up, more of the crisis in