The deadliest was in the central city of Hillah, where a police officer said back-to-back explosions in a busy commercial area killed dozens and wounded up to 90.
He said the attack started with a roadside bombing which was followed by a car bomb explosion when rescuers rushed to the scene.
Another police officer said a car bomb blast at the gates of the nearby city of Karbala killed at least six people and wounded 20 just hours earlier.
Among the victims in the Hillah bombing were Shi'ite mourners commemorating the 17th century martyrdom of the Prophet Mohammed's grandson, Imam Hussein.
Three policemen were killed when a suicide bomber drove his explosives-laden car into a police checkpoint in the city of Fallujah.
And in the northern city of Mosul, a parked car bomb went off next to a passing police patrol, killing two people, police said.