A wave of car bombings rocked central and northern Iraq on Monday, killing at least 57 people, the police and officials said, and extending the deadliest eruption of violence to hit the country in years. In Diyala Province, three parked car bombs exploded around a market in the town of Jidaidat al-Shatt. The blasts killed 15 people and wounded 46. Another car bomb went off near a market in the northern Baghdad suburb of Taji, killing seven shoppers and wounding 25. In the northern city of Tuz Khurmato, a car bomb killed three people and wounded 22. In the evening, more car bombings exploded in the northern city of Mosul, killing at least 24 people and wounding 114, mostly at security checkpoints, said the Nineveh provincial governor, Atheel al-Nujaifi. A suicide car bomber also struck a security checkpoint near Madaen, about 12 miles southeast of Baghdad, killing four soldiers and wounding 10. Four people were killed when a bomb exploded in the Shiite neighborhood of Sadr City in Baghdad late Monday.