A suicide car bombing near a cafe and another bomb attack inside it killed eight people in central Iraq on Thursday, while bomb attacks in Baghdad killed four others, security officials said.

The suicide bomber attacked a cafe in the village of Garma, north of Baquba in Diyala province, police Lieutenant Colonel Ahmed al-Karkhi said.

A second bomb exploded inside the cafe as the casualties were being carried out, Karkhi said, putting the toll from the two blasts at eight dead and 18 wounded.

A car bomb exploded on Thursday afternoon in the Hurriyah area of north Baghdad, killing two people and wounding nine, an interior ministry official said.

A medical source at Kadhimiyah hospital said it had received two bodies and 12 wounded.

And a bomb targeted an Iraqi army patrol in Sadr City in north Baghdad, killing two people and wounding 13, the ministry official said.

Thursday's bombings come after a wave of apparently coordinated bombing and shooting attacks in seven different provinces across Iraq killed 38 people and wounded more than 170 on April 19.

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.

Al-Qaeda's front group the Islamic State of Iraq claimed the April 19 attacks in a statement on the Honein jihadist website the following day.

"We assure you that this invasion is the beginning of what is waiting for you in the next days, and one phase in a blessed series that has been launched, and will not stop until God judges between us" and the Shiites, the statement said.

There was no immediate indication that the latest attacks in Baquba and Baghdad were coordinated.

Violence in Iraq has fallen sharply from its peak in 2006 and 2007, but attacks still continue across the country. In March, 112 Iraqis were killed, according to government figures.