A man walks through a destroyed residential area of Saraqib, Syria, on Monday, September 9, following repeated airstrikes by government forces. More than 100,000 people have been killed in Syria since a popular uprising spiraled into a civil war in 2011, according to the United Nations. The Syrian government&#39;s suspected use of chemical weapons in a deadly August 21 attack has prompted the United States to urge military action against the regime. Click through to view the most compelling images taken since the start of the conflict.