A spate of bombings and shootings in Baghdad and a restive province north of the capital killed nine people on Thursday morning, security and medical officials said.

In Baghdad, a car bomb at 8:00 am (0500 GMT) killed at least three people and wounded 11 others near a police station in the predominantly Shiite neighbourhood of Hurriyah, officials said.

A series of separate shootings and bombings in Diyala province killed six people and wounded six others. The victims included an army officer gunned down inside his house and two guards of Diyala University's president killed in bomb blasts as they were escorting him in a convoy.

The latest violence comes with Iraq mired in a series of interlocking crises that have raised tensions as anti-government protesters have blocked off a key trade route in more than two weeks of ongoing rallies.

No group immediately claimed responsibility for Thursday's attacks but Sunni militants often target Shiite areas and official targets in a bid to destabilise the government and re-ignite the brutal sectarian conflict that engulfed Iraq from 2005 to 2008.

Violence is down in Iraq from its peak in 2006 and 2007, but attacks remain common, especially in Baghdad and Diyala, which has the highest per capita rate of civilian deaths nationwide according to monitor group Iraq Body Count.