An opposition activists shows a sign reading “Cuban mercenaries out of the National Guard” during a protest in front of the OAS headquarters building in Caracas on March 3, 2014. The latest wave of protests, which erupted on February 4 and up to now has left at least 18 people killed and 250 injured, has grown into the biggest threat to President Nicolas Maduro since he succeeded socialist icon Hugo Chavez last year. AFP PHOTO/JUAN BARRETO