By Renee Maltezou ATHENS (Reuters) - In a last-minute drive to assure European Union partners that it is getting to grips with a mass influx of refugees, Greece released aerial photographs on Tuesday of new registration centres for migrants on its northern Aegean islands. The move is part of Athens' efforts, ahead of an EU summit starting on Thursday, to rebuff criticism by Germany and other EU governments that it has done too little to manage the flow of hundreds of thousands of people arriving on its shores. The biggest migration crisis in Europe since World War Two has provoked strains and recriminations between EU governments.