An environment supporter is arrested during a rally after Chile's regional environmental commission approved a hydro-power dam project, in Santiago May 9, 2011. Chilean environmental regulators on Monday gave the green light to the divisive $3.5 billion HidroAysen hydro-power dam project that promises to help ease energy squeezes, but opponents say it will ruin pristine Patagonian valleys. REUTERS/Ivan Alvarado (CHILE - Tags: POLITICS CIVIL UNREST ENVIRONMENT)