A 20-year-old Jersey City man was arrested and a loaded gun was recovered late Saturday night after a car stolen out of Elizabeth was located in Jersey City, authorities said. After receiving a “be-on-the-lookout” alert for a red Mercedes Benz that was carjacked by an armed assailant in Elizabeth and had entered Jersey City, police officers located the unoccupied car at the intersection of Bramhall Avenue and Pine Street at 10:22 p.m. Saturday, Jersey City spokeswoman Kimberly Wallace-Scalcione said. Rahmel Belle, 20, was nearby and attempted to flee on foot, but officers gave chase and found …