( CNN ) -- A series of car bombs ripped through parts of Baghdad Monday evening , killing at least 28 people and wounding dozens in the latest deadly incident in violence-torn Iraq , police said . Nine car bombs detonated in the Iraqi capital , at least some of them in several Shiite Muslim neighborhoods . In addition to those killed , at least 106 were injured , police said . `` Yes , another day of coordinated attacks in the capital , '' police Capt . Ali al-Lami told CNN . It was n't clear who was responsible , he added . Monday 's violence came after at least 88 people were killed and more than 300 were injured in bombings and other attacks throughout the country on Saturday and Sunday , according to police officials . The weekend attacks prompted a U.N. envoy to call on the nation 's leaders to take action to stop the `` accelerated surge in violence and bloodshed . '' More than 5,000 civilians have died and 12,000 have been wounded in terrorist attacks and other violence in Iraq in 2013 , the U.N. Mission in Iraq reported last month . The region around Baghdad has been the hardest-hit , the agency said . The United Nations has said 979 Iraqis were killed and 2,133 were wounded in acts of terrorism and violence last month alone . `` In the aftermath of yet another series of bloody attacks that indiscriminately hit pilgrims , schoolchildren , journalists , as well as ordinary citizens trying to go about their daily lives , the special representative of the United Nations secretary-general for Iraq , Mr. Nickolay Mladenov , called on political , religious and civil leaders to work together with the security forces and take joint action to halt the accelerated surge in violence and bloodshed , '' the U.N. Assistance Mission for Iraq said in a statement issued Sunday . Iraq has been struggling with deep sectarian divisions between its Shiite and Sunni populations , as well as the ethnic divisions between Arabs and minorities such as Kurds . Iraq has seen a sharp increase in tension between its Shiite and Sunni populations since April , when security forces raided a site used by Sunni protesters to demonstrate against the Shiite-led government . Sunnis , who represent a minority of Iraqis , have felt politically marginalized since the overthrow of Saddam Hussein in 2003 . Shiites , who make up a majority of Iraqis , now dominate the government . CNN 's Jason Hanna contributed to this report .
Police : At least nine car bombs exploded in Shiite neighborhoods in Baghdad . The bombings come after two weeks in which people were killed in various attacks in Iraq . Iraq : More than 100 people have been killed in Iraq so far this year .