WASHINGTON – A federal strike force charged 91 doctors, nurses and other licensed medical professionals across the country in connection with phony bills totaling nearly $430 million – the latest in a series of busts by the Obama administration to attack rising government losses to health care fraud.

“We are fighting back,” Attorney General Eric H. Holder Jr. said Thursday. “Today’s takedown underscores the fact that federal efforts to combat health care fraud have been more strategic, more comprehensive, more effective.”

His comments echoed those by President Barack Obama during the debate Wednesday with Republican presidential nominee Mitt Romney. Obama said that, under his administration, “we went after medical fraud in Medicare and Medicaid very aggressively, more aggressively than ever before.”