Plumes of smoke after an explosion near Syrian army barracks in Damascus, according to this video posted to a social media website.<br/> <br />Rebels are claimingresponsibility for the attack which wounded four people<br/> <br />Rubble and debris near the blast site. Syrian state television described the explosion as an "act of terrorism"<br/> <br />Rebels have stepped up their attacks on roadblocks in recent weeks.
