Bomb attack kills 18 in two Iraqi families

An early morning bomb attack aimed at two Shi'ite brothers near Baghdad has killed 18 members of the family, including five women and six children.

Fifty people have died after a wave of coordinated car bombs ripped through Baghdad. (AAP)

Militants have bombed adjacent houses belonging to two Shi'ite Muslim brothers south of Baghdad, killing 18 members of their families, security and medical officials say.

The bombs targeted the houses in the town of Latifiyah, just south of Baghdad, early on Wednesday morning, an army officer and a doctor at a nearby hospital said.

Among the dead were at least five women and six children.

Latifiyah lies within a confessionally-mixed region south of Baghdad known as the "Triangle of Death", so named for the brutal violence that plagued the area during the peak of Iraq's sectarian war in 2006 and 2007.

Last week, another attack on a Shi'ite Muslim family in the town killed at least five people.

Meanwhile three roadside bombs north of Baghdad killed five soldiers as the Iraqi capital reeled from a spate of car bombs the previous evening targeting Shi'ite neighbourhoods.

On Wednesday morning, a trio of blasts went off near a passing army patrol in the mostly-Sunni town of Sariyah, just north of Baghdad, killing five soldiers and wounding seven others, officials said.

More bombings in former dictator Saddam Hussein's hometown of Tikrit killed a young boy and wounded a woman.

The latest bloodshed came after a wave of attacks across Iraq concentrated in the capital killed 54 people and left more than 100 wounded the previous evening.

A dozen car bombs, which all went off after 6. 00pm on Tuesday (0100 AEST Wednesday) and targeted Shi'ite neighbourhoods of the capital, killed 43, security and medical officials said.

The blasts hit a range of civilian targets, from an ice cream shop in the central commercial district of Karrada to a popular market in the northern neighbourhood of Mammal.

Another car bomb went off near a Shiite mosque in eastern Baghdad.

And a vehicle rigged with explosives in Aaliyah, in the north, was detonated near a crowded wholesale fruit and vegetable market. It badly damaged several cars and more than a dozen shops, an AFP journalist at the scene said.

The bombings were the latest in a series of attacks timed to coincide with people visiting cafes and other public areas during the evening.