Iraqi authorities say bombs have exploded in several cities as Shi'ites gathered for annual religious processions, killing at least 44 people and wounding many others.

They said four bombs targeted Shi'ite pilgrims in and around Baghdad, killing at least 18 people, while two car bombs killed at least five people in the mainly Shi'ite town of Balad to the north. Officials said two car bombs also detonated in the central city of Hilla, killing at least 21 people.

Wednesday's bombings were the latest in a series of attacks on Iraqi Shi'ites this month. Shi'ite pilgrims have been gathering for processions to commemorate the death of a revered 8th century imam. Minority Sunni insurgents have repeatedly bombed such processions in the past.

The latest bombings also coincide with an Iraqi political crisis in which minority Sunni and Kurdish lawmakers have been trying to unseat Shi'ite Prime Minister Nour al-Maliki, accusing him of monopolizing power in Shi'ite hands.

Violence in Iraq has declined significantly since its peak in 2006 to 2007, but attacks remain common, especially in Baghdad.