Baghdad ( CNN ) -- At least five people were killed and 30 others wounded Friday after a bombing outside a Sunni mosque in northeastern Baghdad , police said . The blast took place as worshippers were leaving the mosque in the al-Rashidiya neighborhood following Friday prayers , police said . There has been an uptick in violence lately between Shiites and Sunni Arabs , and the persistent tensions have stoked widespread fears that the simmering hostilities , which raged during the Iraq War , could morph into a civil war . Since the overthrow of Saddam Hussein 's government , Sunni Arabs have been politically marginalized , and Shiites , who represent a majority of Iraqis , have emerged with more power . There have been protests for months by Sunni Arabs against the Shiite-led government and its prime minister , Nuri al-Maliki . The anger has escalated since a confrontation last week between police and protesters in Hawija . More people died violently in Iraq in April than in any other month since June 2008 , the United Nations said Thursday . A total of 712 people died and 1,633 more sustained injuries `` in acts of terrorism and acts of violence , '' the U.N. Assistance Mission for Iraq said . Civilians made up most of the victims -- 595 -- and 1,438 civilians were injured . READ MORE : Iraq at crossroads as bombs explode . READ MORE : April the deadliest month in Iraq in 5 years .
The mosque is in northeastern Baghdad . There 's been an upsurge in sectarian violence in Iraq . April was the deadliest month in nearly five years , United Nations says .