Description:A car bomb hit Syria's second city of Aleppo on Sunday (March 18), killing at least three people and wounding 25, according to the Syrian observatory for Human Rights. The blast in Aleppo, just a day after twin blasts in Damascus left 27 people dead, occurred behind a post office in what Syrian state television described as a residential area. There have been a series of suicide attacks that have struck Damascus and Syria's second city Aleppo over the past three months.(0:41)