Daniels Herrera kept quiet on his long walk home from work following violent protests in the Colombian capital Bogota last week, fearful his Venezuelan accent would give him away.

The 26-year-old had arrived in the sprawling city high in the Andes almost two years ago, one of more than a million Venezuelans who have fled crime and an economic meltdown at home to seek refuge in Colombia.

Herrera never expected to feel more unsafe here than in Venezuela, which has one of the highest rates of violent crime in the world, but that changed when violence erupted in Bogota during a nationwide strike and authorities imposed a citywide curfew.