Two other rocket launchers mounted on donkey carts were found within hours - one about 30 yards from the Italian Embassy and another near the Academy of Fine Arts, both in the Waziriya neighborhood north of downtown. Iraqi police and U.S. troops were seen securing those weapons, which apparently had not been fired.
One man was carried away bleeding from the Palestine Hotel, where many foreign journalists and U.S. workers are staying. There were no reports of other casualties at the Palestine or the Sheraton Hotel across the street.
"We've had numerous incidents where they use these low tech tactics and sometimes we stop them and sometimes they get through," Brig. Gen. Mark Kimmitt, U.S. deputy chief of operations in Iraq, told the CBS News Early Show.
Kimmit said the identity and organization of the attackers was unknown, but he suspected a "network of former regime loyalists, people who have everything to lose by a free and democratic Iraq."
In other recent developments:
The attacks in Baghdad occurred at the height of Operation Iron Hammer, the U.S. military counteroffensive against rebels in and around the capital. The U.S. commander in the capital, Brig. Gen. Martin Dempsey, said Thursday that the 12-day crackdown had contributed to a 70 percent decrease in rebel activity.
But some reporters and analysts have suggested the massive attacks on fixed targets are a poor response to sporadic violence by terrorists. Iraqis living near some of the areas hit express resentment about strikes on areas they say are free of insurgent activity. Even some military commanders have said the offensive is intended to scare terrorists as much as it means to kill them.
"I think probably we're probably endearing ourselves to the good Iraqis," Kimmel, asked about Iron Hammer, told the Early Show. "These are very precise operations, very surgical operations and if I was a good Iraqi citizen, I would appreciate seeing a house across the street from mine that had been used for terrorist attacks to shoot mortars from to shoot I.D.S from — I would like to see that house go away."
The rocket attacks appeared intended to demonstrate that the operation hasn't defeated the rebels. There were no immediate reports of arrests.
The attacks both occurred about 7:20 a.m. At least eight rockets were fired at the Oil Ministry, but only two of them detonated, according to Col. Peter Mansoor of the U.S. 1st Armored Division. CBS News Correspondent Elizabeth Palmer reports the rockets inside were detonated by a car battery.
After the explosions, U.S. soldiers were seen searching donkey carts around Baghdad.
The ministry was closed Friday for the Muslim day of prayer, and there were no reported injuries there.
Mansoor said one rocket hit the Palestine Hotel, but at least five rocket holes could be seen on the eighth, 15th and 16th floors of the 18-story structure. Another rocket hit the Sheraton.
Ziyad, a 25-year-old Iraqi man who was staying with his bride Rownaq at the Palestine for their wedding night was two doors down from one of the 15th-floor impacts.
"We were sleeping when we heard the sound of a rocket," he said. "This is our wedding present."
The hotels are among the best-protected in Baghdad, with several security checkpoints on the approaches, blast barriers on surrounding streets and U.S. armored personnel carriers stationed outside. They stand in front of Firdaus Square, where Iraqis famously toppled a statue of Saddam Hussein on April 9.
The ministry and hotel are among the most heavily guarded buildings in Baghdad, "which just shows the sophistication of the enemy. He's a very adapted enemy and he's going to use whatever he can to slip through some of our defenses," Kimmit said.
Employees of U.S. agencies met in the Palestine lobby for impromptu security briefings from military consultants.