Iraqis are witnessing the worst violence to rock their country in five years.Bombings and other attacks against Sunni Muslim and Shi’ite targets are stoking sectarian tensions.One major reason is the civil war next door in Syria. Douglas Ollivant of the New America Foundation.“It is no accident that we are seeing more bombings in Iraq now because of the money and the weapons that are going to the Syrian Free Army,some factions of which are aligned with al-Qaida.”Amateur video posted online shows rebel fighters in Syria from the al-Nusra Front pledging allegiance to al-Qaida.The group receives support from al-Qaida in Iraq, and militants frequently cross the porous Iraqi-Syrian border.Michael Rubin is with the American Enterprise Institute.“The Iraqis are scared to death about the backlash and the back flow of some of these militants and al-Qaida related groups.”Rubin calls Syria an underground railroad for militants to get into Iraq.In 2006-2007, tens of thousands of Iraqis died in sectarian conflict, but this time there are no U.S. troops to help quell the violence.For months, Iraq’s minority Sunnis have staged anti-government demonstrations.