Attacks north of Baghdad on Monday, including a car bomb detonated by a suicide bomber, killed six people just days ahead of the 10-year anniversary of the US-led invasion of Iraq.
The latest violence, which also comes with weeks ahead of the country's first elections in three years, will raise fresh questions about the capabilities of Iraq's security forces amid an apparent spike in unrest.
In the deadliest attack, a suicide car bomb near a police checkpoint in Baladruz, 75 kilometres (45 miles) northeast of Baghdad, killed five people and wounded 20 others, security and medical officials said.
Three policemen were killed and 17 wounded in the evening attack.
Separate attacks in the northern city of Kirkuk and the town of Madain, just south of Baghdad, left one person dead and five people wounded, according to officials.
Britain-based Iraq Body Count has said that more than 112,000 civilians have been killed since the 2003 invasion, while a study published in The Lancet put the figure at 116,000 from 2003 up to December 2011, when US forces pulled out.
Since the withdrawal, Iraq's military and police are consistently described by Iraqi and American officials as capable of maintaining internal security, but not yet fully able to protect the country's borders, airspace and maritime territory.
Attacks remain common, however, albeit at markedly lower levels than during the peak of Iraq's sectarian war.
In February, 220 people died in attacks in Iraq, according to an AFP tally based on reports from security and medical officials.