At least seven people were killed on Sunday in a series of attacks in Iraq, most of which were concentrated in predominantly Sunni areas north of the capital, officials said.

The latest unrest is part of a sustained surge in bloodshed that is Iraq's worst since 2008, when it was emerging from a brutal sectarian war, and which has left more than 2,000 people dead already this year.

It has primarily been driven by anger in the minority Sunni Arab community, which alleges it is unfairly targeted by the Shiite-led government and security forces, as well as spillover from the civil war in neighbouring Syria.

The deadliest of Sunday's violence struck in the restive northern province of Nineveh, where three separate attacks killed four people, including two soldiers who were on patrol in the south of the province.

Elsewhere in Iraq, a roadside bomb in Tikrit, also north of Baghdad, killed two civilians, while a university professor was shot dead in the Shiite-majority city of Kut, south of the capital.

Diplomats and analysts have urged the authorities to do more to reach out to the Sunni community because while they say there is little active support for militants, frustration with the authorities means they are less likely to report suspected insurgents or provide other information.

But with elections looming on April 30, political leaders including Prime Minister Nuri al-Maliki, who is Shiite, have been loath to be seen to compromise.