British Intelligence cites four such attacks since 2012 . ` ` A clear pattern of regime use , '' says the Intelligence Division head . However , he added , `` the reported symptoms of the patients , in addition to the epidemiological pattern of the events -- characterised by the massive influx of patients in a short period of time , the origin of the patients , and the contamination of medical and first aid workers -- strongly indicate mass exposure to a neurotoxic agent . The August 2012 incident poses ` ` a very , very compelling case '' But skeptics - -- about America 's WMD ?
British Intelligence cites four such attacks since 2012 . ` ` A clear pattern of regime use , '' says the Intelligence Division head . The August 2012 incident poses ` ` a very , very compelling case '' But skeptics - -- about America 's WMD ?