MADRID, Spain — A two-year investigation into the Madrid train bombings concludes the terrorists who carried out the blasts were homegrown radicals acting on their own rather than at the behest of Osama bin Laden's Al Qaeda network, two senior intelligence officials said.Spain still remains home to a web of radical Algerian, Moroccan and Syrian groups bent on carrying out attacks — and aiding the insurgency against U.S. troops in Iraq — the Spanish intelligence chief and a western official intimately involved in counterterrorism measures in Spain told The Associated Press.