
Raul Arboleda / AFP - Getty Images
Activist fights for a U.S. flag with a police officer during a protest on April 13 at University of Antioquia in Medellin. They were protesting the VI Summit of the Americas in Cartagena, Colombia.

Raul Arboleda / AFP - Getty Images
Protesters carry a U.S. flag decorated with swastikas April 13 at Antioquia University in Medellin, Colombia, during a demonstration against the VI Summit of the Americas.

Albeiro Lopera / Reuters
Activists burn the U.S. flag at Antioquia University in Medellin, on April 13 as they protest against the VI Summit of the Americas which will take place in Cartagena, Colombia April 13-15.

Albeiro Lopera / Reuters
Police spray water cannons at activists during a protest April 13 at University of Antioquia in Medellin, Colombia. They were protesting against the VI Summit of the Americas taking place April 13-15 in Cartagena, Colombia.
Colombia president to Obama: Don't ignore neighbors
Related article on Summit of the Americas
•Sign up for the msnbc.com Photos Newsletter