Dozens of Kenyan athletes stormed the athletics federation headquarters in Nairobi on Monday, locking out officials and demanding top Athletics Kenya (AK) bosses step down in the wake of allegations of graft and doping cover-ups, an official said. Kenya, boasting some of the world's finest middle and long-distance runners, has in recent years been rocked by a spate of failed drug tests and the athletics federation has drawn criticism for not doing enough to tackle doping. (For more sports news andupdates, followAhramOnlineSportson Twitter at@AO_Sportsand onFacebookatAhramOnlineSports.) http://english.ahram.org.eg/News/170532.aspx