The attacks yesterday were the latest in a protracted surge in violence that has forced Iraq to appeal for international help in combatting militancy just months before its first general election in four years.
The deadliest attacks struck in Baghdad, where a wave of evening bombings targeted civilians in both Sunni and Shiite neighbourhoods of the capital.
From the evening onwards, four car bombs and three roadside bombs hit areas ranging from the Shiite slum neighbourhood of Sadr City in northeast Baghdad to the western Sunni suburb of Radhwaniyah.
Overall, at least 21 people were killed and more than 60 wounded, according to security and medical officials.
The explosions are part of a months-long trend of attacks timed to go off in the evening as Iraqis mass at public meeting places, with restaurants, cafes, and football pitches all hit as violence has surged.
In previous months and years, attacks had typically been timed to coincide with morning rush hour.
No group immediately claimed responsibility for the bloodshed, but Sunni militants linked to al-Qaeda often set off coordinated bombings across Baghdad, ostensibly in a bid to undermine public confidence in the Shiite-led government.
The unrest is part of a surge in bloodshed that has pushed violence to its highest level since 2008, when Iraq was recovering from the worst of its Sunni-Shiite sectarian war.
Prime Minister Nuri al-Maliki has called for Washington's help in the form of greater intelligence sharing and the timely delivery of new weapons systems in an effort to curb the bloodshed.
In addition to failing to stem the bloodshed, authorities have also struggled to provide adequate basic services such as electricity and clean water, and corruption is widespread.