Tuesday's violence was the deadliest to strike Iraq in nearly a month, rocking towns and cities spanning the northern oil-rich hub of Kirkuk and the southern shrine city of Karbala from 7:00 am (0400 GMT).

In central Baghdad, a car bomb exploded in the parking lot opposite the foreign ministry, despite dramatically heightened security measures in the capital in preparation for the March 27-29 Arab League summit.

Six people were wounded in the blast, but it underscored concerns over Iraq's ability to maintain security for the meeting. Tuesday's deadliest attacks occurred in Kirkuk and Karbala, where 26 people died in total.

In ethnically-mixed Kirkuk, a car bomb targeting a police office killed 13 people and wounded 50 others, according to police Major Salam Zangana. All of the fatalities were police, as were the vast majority of those hurt.

The explosion, which was followed minutes later by a smaller car bomb, also badly damaged dozens of police cars. "We have also received parts of bodies, but we do not know who they belong to," said Mohammed Abdullah, a doctor at Kirkuk hospital.

In Karbala, two roadside blasts at the entrance to the city killed 13 people and wounded 48, according to provincial health spokesman Jamal Mehdi.

Police spokesman Major Alaa Abbas of Karbala, which is south of Baghdad and home to the shrines of revered Shiite clerics Imam Hussein and Imam Abbas, confirmed the toll.

A car bomb in the central town of Hilla, also south of the capital, killed two people and wounded 31 others, provincial security committee chief Haidar al-Zambur said. The toll was confirmed by Ali Mohammed at Hilla hospital.

And hours before the foreign ministry attack in Baghdad, a car bomb set off by a suicide attacker in the centre of the capital killed four people and wounded eight, security and medical officials said.

Another car bomb in Ramadi, capital of western Anbar province, killed two people and wounded 11, according to police and medical officials. A roadside bomb blast later in the city targeting Anbar governor Qassim Mohammed Abed left two wounded, though Abed was unharmed.

Separate gun and bomb attacks in Salaheddin province killed four people, including a city councillor, police said.

Bombings in the main northern city of Mosul, the refinery town of Baiji, and the northern towns of Baquba, Daquq and Al-Dhuluiyah left 25 people wounded. Another car bomb in the northern city of Samarra left no casualties.

.The attacks come on the ninth anniversary of the beginning of the US-led invasion of Iraq which ousted Saddam Hussein, and just days before Baghdad hosts an Arab League summit, the first meeting of the 22-nation body to be held in the capital since Saddam's 1990 invasion of Kuwait.