The second attack struck north of the Baghdad Hotel, which is mostly occupied by foreign security contractors.
American officials said they were also uncertain why the 35 Americans were removed from their Baghdad hotel.
The soldier also said several rockets were fired at the adjacent Baghdad Hotel, but all missed.
A second rocket wounded three security guards at the Baghdad Hotel, a frequent target for attack.
At the same time, explosions also struck outside the Baghdad Hotel, hundreds of feet north of the square.
He said the attack on the Baghdad Hotel was not terribly successful, at least not in comparison with other attacks.
Civic groups and Shiite leaders held separate meetings in Baghdad hotels to discuss the future constitution.
The U.S. later bombs the Baghdad hotel where these journalists are staying.
They checked into a Baghdad hotel and stayed until Saturday, coming and going as they liked.
The blast takes place in Baghdad Hotel.