In Anbar province, at least four people were killed and 15 wounded at dawn when Iraqi army pounded Garma twon near the militant-seized city of Fallujah, some 50 km from Baghdad, Xinhua quoted a provincial police source as saying.
Separately, the army tanks and artillery pounded several neighbourhoods in Ramadi city, some 110 km from Baghdad, leaving eight civilians killed and 11 wounded, the source said.
Gunmen also attacked an army checkpoint in central Ramadi in the morning and killed three soldiers and wounded five, the source added.
Also in Ramadi, a security force opened fire on a suicide bomber and forced him to blew up his explosive vest before he reaching his target at an army base, he added.
In Baghdad, two roadside bombs went off in a quick succession in Doura district, leaving one civilian killed and five wounded, a police source said.
In a separate incident, a soldier was killed and another wounded in a roadside bomb near their patrol in Abu Ghraib area, some 25 km from Baghdad, a police source said.
In addition, another soldier was killed and two others were wounded when a roadside bomb struck their patrol in Tarmiyah area, some 40 km from Baghdad, a police source said.
Elsewhere, two police officer were killed when gunmen attacked their car on a main road near the city of Baiji, some 200 km from Baghdad, a local police source said.
In Diyala province, a soldier was killed and another wounded in a roadside bomb explosion near their patrol in the town of Udheim, some 60 km from Baquba city.
Separately, soldiers shot dead a suicide bomber before he reached their checkpoint in Abu Saida area near Baquba.
Iraqi police found a body of a male in his 30s dumped near Diyala river near the city of Baquba, with bullet holes in his head and chest, the source added.
The violence came less than two weeks ahead of landmark parliamentary elections April 30, the first in the country since the withdrawal of US troops in late 2011.