A wave of apparently coordinated bombing and shooting attacks in seven different provinces across Iraq killed at least 38 people and wounded more than 170 on Thursday, security officials said.

It was the deadliest day in Iraq since March 20, when shootings and bombings claimed by an Al-Qaeda front group, the Islamic State of Iraq, killed 50 people and wounded 255 nationwide.

The attacks, which come amid heightened political tension, drew an accusation from the Sunni-backed Iraqiya bloc that security measures were insufficient, and that Prime Minister Nuri al-Maliki, as head of the armed forces, was responsible for the deficiency.

Twenty-three civilians, 10 police, three members of an anti-Qaeda militia and two soldiers were killed in dozens of attacks, including 14 separate car bombings, 13 other bomb attacks and three suicide bombings.

Bombings in and around Baghdad killed at least 17 people and wounded 106, an interior ministry official said.

A car bomb targeting Health Minister Majid Hamed Amin's convoy in Haifa Street in the heart of the capital killed two civilians and wounded nine people, including four of the minister's guards.

Four more car bombs and two roadside bomb in Baghdad killed nine people and wounded 62.

In Taji, north of the capital, two roadside bombs, two car bombs and a suicide bombing killed six people and wounded 29, and a suicide bomber in Tarmiyah, also north of Baghdad, blew up a vehicle by an army base, killing one soldier and wounding six.

In Mussayib, in Babil province, an army major and four other soldiers were wounded by a roadside bomb, a police major said.

In northern Iraq, bombings in Kirkuk province killed 10 people and wounded 29, police said.

A car bomb against the convoy of police Brigadier General Taha Salaheddin south of Kirkuk city killed two police and wounded 15 other people, a high-ranking police officer said on condition of anonymity.

Another car bomb in the city centre killed two police and wounded three.

A police source said that a Kurdish man was shot dead 40 kilometres (25 miles) south of Kirkuk, while three roadside bombs wounded three Sahwa members 45 kilometres (18 miles) west of the city, and two policemen were wounded by a roadside bomb in Kirkuk.

Six bombs against houses in the town of Malha, 40 kilometres (25 miles) northwest of Kirkuk, killed five people including an army major and wounded six, police Brigadier General Sarhad Qader said.

And in Ramadi in Anbar province, west of the capital, two car bombs against police patrols killed one person and wounded nine, a police source said.

In Baquba, the capital of Diyala province, a suicide bomber blew himself up in the home of police First Lieutenant Mohammed al-Tamimi, killing him and wounding four family members, an Iraqi army lieutenant colonel and Dr Ahmed Ibrahim of Baquba General Hospital said.

A suicide car bomb against a police checkpoint in the city centre killed two policemen and wounded two others.

Another policeman was killed by a magnetic "sticky bomb" in Baquba, and gunmen attacked a police station west of the city, killing one policeman and wounding two others, a police major in Diyala and the medic said.

The army lieutenant colonel said another policeman was killed by gunmen in the town of Al-Mansuriyah north of Baquba, while a bomb against a home in the town wounded three people, and a bomb targeting a home in Ghalbiyah, west of Baquba, wounded three more.

In Samarra, in Salaheddin province, two car bombs exploded near checkpoints of anti-Qaeda militiamen, killing three people and wounding six, militia commander Majid Abdullah and a police lieutenant colonel said.

And a worker at the oil refinery in Baiji in Salaheddin was wounded by militants firing rocket-propelled grenades, a police source said.

In the main northern city of Mosul, capital of Nineveh province, a bomb in a restaurant wounded three people, a police captain said.

The spokeswoman for the Iraqiya bloc, Maysoon al-Damaluji, pointed a finger at Maliki for the weakness of security measures to prevent the bloodshed.

"The continuation of bloody explosions, although it has been already announced that tight security measures have been taken, reflects the weak security plans and the necessity to reconsider them," the MP said in an emailed statement.

"The commander of the armed forces (Maliki) is responsible for providing security and complete safety for citizens," she said.

Political tensions have risen sharply after key Iraqi factions accused Maliki of orchestrating a slide away from the electoral process and towards dictatorship with the arrest last week of election commission chief Faraj al-Haidari, who has since been freed on bail.