Attacks mostly targeting cafes in and around Baghdad killed 17 people, officials said on Friday, the latest violence to spark concern of a revival of all-out sectarian war.
The blasts on Thursday evening struck cafes in a mostly Sunni Arab neighbourhood of Baghdad, the central city of Baquba, and a town south of the capital, and came as Iraq grapples with a longstanding political deadlock and months of protests among the Sunni Arab minority.
In Baquba, one of Iraq's most violent cities, a car bomb went off near a cafe in the centre of the city and, when passers-by rushed to help the casualties, the attackers detonated a second bomb.
In all, 12 people were killed and 35 wounded, security and medical officials said.
Also on Thursday evening, in Baghdad's predominantly Sunni Arab neighbourhood of Adhamiyah, an explosion near another cafe killed four people and wounded 14. Two blasts in the town of Jbela, south of the capital, wounded three.
Elsewhere in Baghdad, separate attacks killed a barber and wounded nine other people.
Iraq has seen an upsurge of violence since the beginning of the year, coinciding with protests among the country's Sunni Arab minority against what the demonstrators see as discrimination by the Shia-led authorities.
Analysts say a failure by the government to address the underlying causes of the demonstrations has given militant groups both a recruitment platform and room to manoeuvre.