Over two dozen people have been killed and more than 150 others have been wounded in a string of bomb attacks across Iraq ahead of Christmas and Ashura.

In the worst Thursday attack in the central Iraqi town of Hilla in Babil Province, twin car bombs killed 15 people, including the provincial councilor, Naama al-Bakri, a senior member of the ruling Dawaa Party, and injured 70 others.

In the town of Karbala, a bomb killed one person and wounded 12 others. The late afternoon attack occurred despite the tight security and presence of some 20,000 police officers there.

The reinforcement in Karbala came amid fears that attacks could continue in the days leading up to Ashura, which marks the martyrdom of the Prophet Muhammad's grandson, Imam Hussein (PBUH).

In Baghdad, eight people were killed and 30 others were injured when two explosive devices went off earlier in the afternoon.

The first bomb was attached to a car near a commemoration ceremony in Sadr city. The incident left five dead and 25 wounded.

The second, which killed three people and injured 20, exploded in Zaferaniya, south of the city center.

Shias are preparing for Ashura, which falls on Sunday, to commemorate the martyrdom in the year 680 of Imam Hussein (PBUH). Hundreds of thousands of pilgrims are expected to travel to the southern city of Karbala, where the holy shrine of Imam Hussein (PBUH) is situated.

In the diverse and tense northern city of Kirkuk, the Chaldean Catholic Church canceled the Christmas Mass, amid fears of terror attacks.

"Christians remain a target for armed groups especially in Mosul, where many people and churches have been targeted. This worries us immensely," said Pascale Warda, an Iraqi Christian and a former Iraqi Minister of Immigration and Refugees, dpa reported.