Defense Secretary Donald H. Rumsfeld said Tuesday that American soldiers have captured a number of people in Fallujah as they start an operation in this Iraqi city where four American military contractors were killed last week. "The forces have cordoned off the city. They have photographs of a good many people who were involved in the attacks against the individuals and they have been conducting raids in the city against high-value targets," Rumsfeld said at a brief news conference. "They have captured a number of people over the last 36 hours. The city is isolated. A number of people have resisted and been have killed. And it will be a methodical effort to find the individuals who were involved," Rumsfeld commented. He also said that American military commanders in Iraq will have additional troops if they request more soldiers during a time of intensifying fighting in Iraq, amid a growing Shiite uprising. Rumsfeld, at the appearance in Norfolk, said that he and President Bush frequently ask commanders in Iraq if they need more forces. He said commanders on the ground, including Gen. John Abizaid, the head of U.S. Central Command, are constantly reviewing the situation. "They will decide what they need, and they will get what they need," Rumsfeld said. **PHOTO CAPTION*** Occupation soldiers take cover during a gunbattle with the Iraqis, Fallujah, Iraq, Tuesday, April 6, 2004. (AP Photo/Murad Sezer)