Protesters attacked Mexico's Attorney General headquarters in the country's capital Wednesday demanding answers after 43 students went missing last month in the violent southern state of Guerrero.<br/> <br />Frustrations were amplified Tuesday after officials confirmed none of the 28 corpses found in a Guerrero mass grave belonged to the missing students.<br/> <br />Violence in Guerrero, the home state of Acapulco, is becoming a major issue for President Enrique Pena Nieto, who took office two years ago pledging to end a wave of violence that has killed about 100,000 people since the start of 2007.
