US troops in Iraq are stepping up their efforts to rid the country of forces loyal to ousted President Saddam Hussein.
The military said Sunday it has begun a new operation called Desert Scorpion to isolate and defeat remaining pockets that seek to delay the transition to a peaceful and stable Iraq. It said the operation targets Baath Party loyalists, terrorist organizations and criminal elements.
A US Central Command spokesman said an undetermined number of people already have been detained in the sweep, which began overnight with extensive raids in the town of Fallujah.
Fallujah, 60 kilometers west of Baghdad, has been a center of armed resistance to US forces.
The early-morning military operation, backed by air cover, began hours after a deadline expired for all Iraqis to turn in their weapons. There were no reports of any serious clashes as US soldiers set up checkpoints and searched houses.
By daybreak, calm had returned to Fallujah, and soldiers were distributing food and humanitarian supplies.
Operation Desert Scorpion follows a massive six-day military assault (called Operation Peninsula Strike) that ended Thursday in central Iraq. It netted about 400 suspected militants. All but about 60 of the detainees have been released.
Thousands of soldiers were involved in last week's raids, the largest US military operation since the end of major fighting in April.
The chairman of the US joint chiefs of staff, General Richard Myers, says coalition forces in Iraq are opposed by five groups, including some sponsored by Iran. He said Saturday that U-S forces generally believe Saddam Hussein survived the U-S led war in Iraq and must be found.
An American forces statement says Saddam Hussein's air force commander, General Hamid Raja Shalah al-Tikriti, has been captured. He was ranked 17th on the most-wanted list of officials of the former Iraqi regime.