Until there is such a body, every country is responsible for the objects its citizens put into space according to the Outer Space Treaty. The interesting legal question to me is why it's on the US (where the satellites were built and from which they're being operated) over India (where the satellites were launched from).
(Which question, btw, shows the need for an international regulatory agency like you're describing.)
(Which question, btw, shows the need for an international regulatory agency like you're describing.)