Local security officials are suspected of conspiring with gang members to kill some missing students who are likely among the charred corpses found in a mass grave in southwest Mexico, authorities said. At least 34 bodies had been buried at the site, and Guerrrero state Attorney General Inaky Blanco said two gang hitmen had admitted killing 17 of the 43 missing students with the help of security officials. Blanco said 29 suspects have been identified so far and that 26 have been arrested, including Felipe Flores, the head of security for the city of Iguala, where students had clashed with police. He said local police had been inflitrated by a criminal gang known as the Guerreros Unidos and that Flores had conspired with a gang leader to order the killings.