A wave of bomb attacks rocked Baghdad and the north of Iraq on Monday evening, as violence killed at least 30 people , state officials told reporters.
Most of the areas hit on Monday evening are Shiite majority areas. At least 10 vehicles rigged with bombs were detonated in eight neighbourhoods, AFP reported.
The violence comes as Shiites across Iraq celebrate thebirth of an important figure in their faith, the Imam Mehdi, in a holy festival called Shabaniya.
Conflicting reports on the number of casualties caused by the bombed have been reported by the major agencies, but at least 30 died in the violence.
According to Iraqi security officials who spoke to AFP, in Baghdad, at least 28 were killed and 121 wounded.
A car rigged with explosives detonated outside a popular supermarket in the commercial district of Baghdad's central Karrada neighbourhood.
According to eyewitnesses, the supermarket was destroyed in the attack and blood could be seen from dozens of meters away, AFP reported.
Two cars loaded with explosives detonated with minutes of each other in the western district of Jihad, killing eight civilians, Reuters reported.
A Shiite mosque and a bus station were also targets for the attacks.
In the northern city of Mosul, a bomb was planted in a cafe and killed five people, according to Reuters, who estimate that Monday's death toll was pushed to 40. A shooting in the northern area was also reported.
As of yet, no one has claimed responsibility for the violence but Sunni militantsoften target Shiite majority areas.
Insurgents, including Al Qaeda's Iraqi branch, often recruit from the disillusioned Sunni minority in Iraq , which has felt sidelined by the Iraqi government since the US-led invasion that removed former Iraqi leader Saddam Hussein  from power.
In December, Sunnis took the street in a protest against Iraqi Prime Minister Nouri Al Maliki, but little was done to appease the minority. As a result, Sunni militants have taken to utilizing violence as a more effective means of getting the government's attention.
Sectarian violence is at its highest point in Iraq since 2008. In May alone, dubbed 'the bloodiest month', over 1,000 people died, according to Reuters.