A wave of explosions has hit Baghdad on Christmas Day. One U.S. soldier was killed by a bomb, and attackers launched mortars at multiple targets around the center of the city. Military officials had been predicting a Christmas-time offensive by Iraqi insurgents. The U.S. military says the soldier was killed by a roadside bomb in central Baghdad late Wednesday.

Early Thursday, numerous mortars and rockets shook the downtown area. A military spokeswoman says three-to-four of them struck the so-called Green Zone, housing the coalition provisional authority.

Roadside Bomb Kills US Soldier in Baghdad - 2003-12-25

A mortar round also hit an apartment building, wounding one woman.

Roadside Bomb Kills US Soldier in Baghdad - 2003-12-25

The Sheraton hotel came under attack Thursday morning for the second time in less than 12 hours. A mortar round hit the hotel around the eighth floor, causing some damage, but no injuries.

Roadside Bomb Kills US Soldier in Baghdad - 2003-12-25

Late Wednesday, another mortar hit the roof of the hotel. No one was injured. The Sheraton is largely occupied by westerners, including many journalists.

The attacks came after a second night of sustained U.S. bombardment of largely uninhabited areas around Baghdad in what has been dubbed Operation Iron Grip.