Sandstorms slowed U.S. and British forces to a crawl and thwarted air missions Tuesday, the Associated Press reported. US-led forces edged closer to the Iraqi capital. Baghdad residents, hunkered down for an eventual battle, woke to howling winds and the distant crash of artillery.

The Army met sporadic resistance on its journey north. A report from the 3rd Infantry Division's headquarters estimated 500 Iraqis were killed during a two-day sweep past the holy Shiite city of Najaf.

At least 20 US troops have been killed and 14 captured or missing since the operation began.
US officials said they believed Iraq is more likely to use chemical or biological weapons against coalition troops the closer they get to Baghdad. The Republican Guard controls the bulk of Iraq's chemical weaponry, most of which can be fired from artillery guns or short-range rocket launchers, according to U.S. officials.

Meanwhile, coalition forces destroyed six satellite jamming devices, which Iraq was using to try to thwart American precision guided weapons, Air Force Maj. Gen. Victor Renuart said.