Sixteen of the victims were in several suburbs of Little Rock in Arkansas, officials said. One other person was killed in the town of Quapaw in the north-east of Oklahoma where officials said many buildings were badly damaged. Tornadoes also struck in Nebraska, Kansas, Iowa and Missouri. President Barack Obama, on a trip to the Philippines, offered his deepest condolences to those affected and said federal emergency officials would be on the ground to help: "Your country will be there to help you recover and rebuild, as long as it takes.