The Pentagon cautioned Russia Tuesday not to tamper with the site of an alleged gas attack in Syria's Aleppo and allow investigators to inspect the site. The global chemical weapons agency, known as the Organization for the Prohibition of Chemical Weapons (OPCW), has said it will...

Russian warplanes attacked rebel-held areas in northern Syria for the first time in weeks Sunday, as Syrian officials said more than 100 people were treated at hospitals for a suspected poison gas attack in the northern city of Aleppo that Damascus and Moscow blamed on rebels. The...

The Syrian Observatory for Human Rights said warplanes struck rebel territory in northwest Syria for the first time since Russia and Turkey agreed to create a buffer zone in September. The British-based activist group said the airstrikes hit the suburbs west of Aleppo city, near Idlib...

Syrian rebels have dismissed government accusations they used poison gas to attack government-held Aleppo city. Rebel commander Abdel-Salam Abdel-Razak says the opposition doesn’t possess poisonous gases or the capabilities to lob them. Abdel-Razak served in Syria’s chemical weapons...