US and allied officials told US Public Radio Saturday that President Bashar Assad had prepared several dozen bombs and shells loaded with the lethal chemical sarin in the past weeks. They were especially alarmed when he fired some half a dozen Scud missiles at rebel areas because they could carry chemical warheads. CIA contractors are training rebels in Jordan on how to identify and safeguard chemical weapons that are located in dozens of sites around the country. The Czech Republic, which has expertise in chemical weapons, is taking the lead in the rebel training effort, officials said.