BUENOS AIRES, Argentina, Rabi'I 03, 1437, December 14, 2015, SPA -- At least 43 police officers were killed Monday when a bus in a convoy in northern Argentina blew a tire and veered off the side of a bridge, falling at about 65 feet (20 meters) in an accident that brought the sad state of the South American nation's roads into focus, AP reported . The bus was one of three carrying police near Salta, a city about 932 miles (1,500 kilometers) north of Buenos Aires. The National Gendarmerie officers, a special police force typically charged with patrolling frontier regions, were on their way to Jujuy, a region in northern Argentina that borders Bolivia. Security Minister Patricia Bullrich, who toured the scene, told reporters that an initial investigation found that the right tire of the bus ruptured. "This is a tragedy. We are going to work to make sure gendarmes are better equipped," Bullrich said. Local television images showed rescue crews working around the overturned bus, which authorities said was carrying around 60 people. Gustavo Diaz, head of a group of volunteer firefighters in the area, told Argentine state agency Telam that 20 police were injured and were being treated in area hospitals. Authorities also warned the death toll could rise. --SPA 23:58 LOCAL TIME 20:58 GMT www.spa.gov.sa/w