The Organization for the Prohibition of Chemical Weapons has blamed the Syrian government for carrying out three attacks involving chemical agents in March 2017 in northern Syria. The OPCW has previously concluded that chemical weapons were used in the war, but did not have the mandate to name perpetrators. Syria and its military backer Russia have repeatedly denied using chemical weapons and have accused rebel groups of staging attacks to implicate Syrian forces. Hundreds of thousands have been killed, and over 10 million displaced, since the war began in 2011. The vast majority of civilian deaths have been from Syrian and Russian airstrikes.