PORT-AU-PRINCE, Haiti—A truck carrying gasoline exploded in northern Haiti, killing more than 50 people and injuring dozens of others, officials said Tuesday. The blast occurred late Monday in the city of Cap-Haitien, Prime Minister Ariel Henry said, adding that he was devastated. “Three days of national mourning will be decreed throughout the territory, in memory of the victims of this tragedy that the entire Haitian nation is grieving,” he said on Twitter. Henry said his administration was deploying field hospitals to the area to help those affected. Dozens of bodies lay on the street hours after the explosion as a small crowd stood around them. No further details were immediately available. Police didn’t immediately return calls requesting information. Patrick Almonor, deputy mayor of Cap-Haitien, told The Associated Press that at least 53 deaths and more than 100 injured have been reported following the explosion that burned around 20 homes near …