The U.N. human rights office said on Tuesday that 306,887 civilians had been killed in Syria during the conflict since March 2011, or about 1.5 % of its pre-war population, in what it said was the highest estimate yet.
Syria's conflict sprang out of peaceful protests against President Bashar al-Assad's rule in March 2011 and morphed into a multi-sided, protracted conflict that sucked in world powers.
