An Ecuadorian presidential candidate known for speaking up against corruption has been shot and killed at a political rally in the capital, an attack that comes amid a wave of startling violence in the South American country.

QUITO, Ecuador (AP) — An Ecuadorian presidential candidate known for speaking up against corruption was shot and killed Wednesday at a political rally in the capital amid a wave of startling violence in the South American country

President Guillermo Lasso confirmed the assassination of Fernando Villavicencio and suggested organized crime was behind his slaying. Villavicencio was one of eight candidates in the Aug. 20 presidential vote, though not the frontrunner. The politician, 59, was the candidate for the Build Ecuador Movement.

“I assure you that this crime will not go unpunished,” Lasso said in a statement. “Organized crime has gone too far, but they will feel the full weight of the law.”

Ecuador’s attorney general’s office said a suspect in the assassination of Villavicencio died of wounds after being arrested by authorities.