BAGHDAD — A truck bomb tore through Iraq's Foreign Ministry today, knocking out concrete slabs and windows and leaving a mass of charred cars outside as a wave of explosions around Baghdad killed at least 75 people.

It was the deadliest day in the capital since U.S. troops largely withdrew from cities on June 30 and a major challenge to Iraqi control of Baghdad. A steady escalation of attacks this month has sparked fears of a resurgence of violence ahead of next year's national elections.

The deadliest of the attacks hit near the Foreign Ministry, killing at least 59 people and wounding 250. Officials said the toll may climb as rescue workers dig through rubble and debris. The ministry is just outside the Green Zone, the most heavily protected part of the capital. The officials all spoke on condition of anonymity because they were not authorized to release the information.

The force of the explosion blew concrete slabs off the front of the 10-story building, shattered windows and crushed cars parked outside. Dozens of cars were burned.

The blast was so strong it also damaged nearby buildings. A large area outside the ministry was covered by debris and broken glass and it damaged windows in the parliament building, inside the Green Zone.

A recent rise in bombings has dealt a blow to Iraqi government efforts to restore a sense of normalcy in the capital as the overall level of violence remains low compared with recent years. Iraqi security forces have begun removing concrete blast walls, which have been credited with helping reducing violence. The walls have been coming down in residential and commercial areas with the aim of improving appearance and easing traffic congestion.

The midmorning attacks hit first near the Finance Ministry in northern Baghdad and then minutes later near the Foreign Ministry. Around the same time as the explosion near the Foreign Ministry, mortars struck inside the Green Zone. It was not immediately known what damage the mortars caused or whether there were causalities.

Another car bomb targeted a joint Iraqi police and army patrol just outside the Finance Ministry, killing at least eight people and wounding 22. Twenty-two were wounded.

Another blast in the commercial area of western Baghdad's Baiyaa district killed two people and wounded 16, while a bombing in the commercial district of Bab al-Muadham killed six people.

Gen. Ray Odierno, the top U.S. commander in Iraq, said Monday that he wanted to deploy U.S. soldiers alongside Iraqi and Kurdish troops in northern Iraq.