TO GO WITH AFP STORY BY ANTONIO PAMPLIEGA
Volunteers wear gas masks during a class on how to respond to a chemical attack, in the northern Syrian city of Aleppo on September 15, 2013. For two months, Mohammad Zayed, an Aleppo University student, has been training a group of 26 civilians in the hope they can respond to a chemical attack.  AFP PHOTO / JM LOPEZ (Photo by JM LOPEZ / JM LOPEZ / AFP) (Photo by JM LOPEZ/JM LOPEZ/AFP via Getty Images)