Nine guards have confessed to helping Zetas drug gangsters escape from prison before other Zetas slaughtered 44 rival inmates, a state official said late Monday, underlining the enormous corruption inside Mexico's overcrowded, underfunded prisons. The top officials and as many as 18 guards at the Apodaca prison in northern Mexico had been detained under suspicion that they may have helped 30 Zetas escape during the confusion of a riot early Sunday in which 44 members of the rival Gulf cartel were bludgeoned and knifed to death. Nuevo Leon state public security spokesman Jorge Domene Zambrano said nine of the guards confessed to aiding the escape. He said it appeared the breakout happened before the deadly fight. The massacre in this northern state was one of the worst prison killings in Mexico in at least a quarter-century and exposed another weak institution that President Felipe Calderon is relying on to fight his drug war. Mexico has only six federal prisons, and so sends ...