Gang members brandishing automatic rifles stormed through a town in Haiti’s main breadbasket region, killing at least 70 and forcing over 6,000 to flee, causing widespread shock even in a country grown accustomed to outbreaks of violence.

More people were severely injured in the attack in the early hours of Thursday at Pont-Sonde, in the agricultural region of Artibonite in western Haiti. Gran Grif gang leader Luckson Elan took responsibility for the massacre, saying it was in retaliation…