A government study links many wildfires in the Arizona-Mexico border region to illegal immigrant activity, a finding that Arizona Senator John McCain said backs up comments he made blaming border crossers for some of the blazes

The study was carried out by the independent Government Accountability Office, the investigative arm of the Congress, at the request of McCain, an Arizona Republican who ran for president against Barack Obama in 2008. It found that of 77 human-caused borderland wildfires that were investigated by federal officials from 2006 to 2010, 30 identified illegal border crossers as a suspected source of ignition. Investigators found that half of those fires were lit to signal for help, provide warmth or cook food, although no explicit purpose was given for the remaining fires, which it noted occurred in areas known for drug smuggling. McCain, who sparked a furor in June 2011 by suggesting that illegal immigrants were to blame for some of the wildfires raging near the border, welcomed the report's findings. "This independent GAO study again confirms what U.S. Forest Service and local officials in Arizona have long known: that some of the fires along the Arizona-Mexico border are caused by people crossing the border illegally," McCain said in a statement. "The report further found that firefighting activities have sometimes been delayed while waiting for law enforcement escorts as protection from armed smugglers, which could cause fires to grow larger and more damaging," he added. The GAO report estimates that the federal government spent $33 million fighting human-caused fires along the Arizona-Mexico border between 2006 and 2010.