Riot police are engulfed in flames after protesters threw molotov cocktails during a protest march in Mexico City September 1, 2013. Thousands of protesters took to the streets against the government of President Enrique Pena Nieto who has pinned his hopes of ramping up lackluster growth in Latin America's second largest economy on attracting more investment into the oil industry, and improving Mexico's meager tax revenues. [Photo/Agencies]