WASHINGTON - A rash of tornadoes tore through central US states late Wednesday, killing six people including four teenage boys who died when their Scout camp in Iowa suffered a direct hit, officials said. Lloyd Roitstein, president of the Boy Scouts of Mid-America Council, said the Little Sioux Scout Ranch in Iowa's remote western hills was "virtually destroyed" when the twister touched down at about 6.45 pm Wednesday. He said about 100 staff and boys aged 13 to 17 were in the middle of a week-long leadership training course when it hit, ripping tents off the ground and snapping trees at the 1,800-acre compound. State emergency officials named the four victims as Aaron Eilerts, 14, of Iowa, Josh Fennen, 13, Sam Thomsen, 13, and Ben Petrzilka, 14, all three from Omaha. Reports suggested a further 40 people at the camp were injured. The scouts had a weather radio with them and were ready for the storm. They had also carried out an emergency tornado drill the day before so "they knew what to do, they knew where to go and they performed well," Roitstein said. As the weather worsened they retreated into the camp's bunkhouse and when it was hit set up their own mini-triage unit to help the injured, Iowa Governor Chet Culver told a press conference in Blencoe, Iowa. Their actions "literally saved lives" as they waited for emergency services to cut their way through fallen trees to reach the camp, about a mile from the nearest road, he said, adding: "They were the real heroes, these young men." Roitstein said: "These scouts are going to be the future leaders of our community, and we're so proud of them and what they did to make our terrible situation better and save many lives." Those participating in the training camp were from Iowa, Nebraska and South Dakota, and Nebraska Governor Dave Heineman paid tribute to the "incredible job" of officials and volunteers in responding to the disaster. He described the camp as "devastation - it is very, very difficult to look at. You see that bunkhouse and in some ways its amazing we didn't lose more lives than we did... (the boys) responded in true boy scout fashion."