(CNN) -- A string of bombings mostly in and around Baghdad on Wednesday killed 49 people and wounded 180 others, police said.
Seventeen attacks unfolded in and around Iraq's capital, primarily in Shiite areas, police said. Police believe the strikes -- which killed 46 people -- occurred over a two-hour period and appeared to be coordinated.
Another car bomb killed three police officers in Mosul, in northern Iraq.
The latest violence comes as Iraqi security forces conduct an operation called Revenge for the Martyrs, designed to track down al Qaeda members in and around Baghdad.
Jacqueline Badcock, the U.N. secretary-general's deputy special representative for Iraq, said, "no political goal or grievance can possibly justify this daily bloodshed of innocent civilians."
"This relentless wave of senseless killing has left thousands dead since April and reflects the merciless nature of its authors," she said.
Iraq has endured months of escalating violence stemming from decades-old discord between the nation's Sunnis and Shiites, the two largest branches of Islam.
Sunnis have felt politically marginalized under a Shiite-led government since the ouster of longtime leader Saddam Hussein in a 2003 U.S.-led invasion.
July was the deadliest month in Iraq in the past five years since the peak of sectarian violence in 2006 and 2007. According to the United Nations, 1,057 Iraqis were killed and another 2,326 were wounded in acts of terrorism and violence last month.