Militants shot dead an Iraqi provincial councillor and bombed the education minister's convoy on Wednesday, as violence killed 13 people nationwide ahead of next week's elections.

Iraq is suffering a protracted surge in bloodshed that has killed more than 2,750 people this year, and the April 30 parliamentary vote -- the first since American troops departed in 2011 -- will be a major test for security forces.

In Muqdadiyah, northeast of Baghdad, gunmen opened fire on Diyala provincial councillor Ahmed al-Harbi's two-vehicle convoy, killing him and two guards, police and a doctor said.

And in Kirkuk province, farther north, a bomb exploded near Education Minister Mohammed Tamim's convoy without causing any casualties, Staff Major General Mohammed al-Dulaimi said.

Militants targeted Deputy Prime Minister Saleh al-Mutlak earlier this month and have also attacked other parliamentary candidates and election workers.

North of the city of Mosul, a car bomb exploded in the village of Bayukh, which is populated by members of the Shabak minority, killing seven people and wounding 13, police and a morgue employee said.

The 30,000-strong Shabak community mostly lives in northern Iraq near the Turkish border.

They speak a distinct language and largely follow a faith that is a blend of Shiite Islam and local beliefs, and are periodically targeted by militant groups.

And in the Dhuluiyah area north of Baghdad, two Sahwa anti-Al-Qaeda fighters were shot dead, while a policeman was killed in Tikrit, farther north, police said and a medical source said.

"Security conditions are likely to worsen around the date" of the election, and "violence is likely to continue while the government formation process takes place," said John Drake, a security specialist with risk consultancy AKE Group.

The last parliamentary election took place in March 2010, but a new government was not formed until December -- and key security posts remain unfilled more than three years later.

Ultimately, "it will take a change in government tactics to include much greater community engagement and investment in order to pacify conditions," he said.

Drake said he believes the violence may lower Prime Minister Nuri al-Maliki's chances of a third term.

But Michael Knights, a fellow at the Washington Institute for Near East Policy, said the security situation could be used to draw attention away from other problems.

"Maliki is using the security crisis to shift the debate from public dissatisfaction with governance towards the need to unify behind the present government due to the crisis conditions," Knights said.

"If he succeeds, the security crisis could greatly benefit him."

While security forces were able to keep violence to a minimum during provincial elections last year, they have failed to halt a subsequent year-long surge in unrest.

The heightened violence has been principally driven by widespread anger among the Sunni Arab minority, who say they are mistreated by the Shiite-led government and security forces.

It has also been fuelled by the bloody civil war in neighbouring Syria, which has bolstered militant groups.