Six satellite jamming devices, which Iraq was using to try to thwart American precision guided weapons, were destroyed and have had "no effect" on U.S. military operations, a U.S. general said Tuesday.

President Bush had called Russian President Vladimir Putin on Monday to complain about the alleged sales of high-tech equipment, which could pose a threat to American troops. The Kremlin denied the allegations that Moscow had broken U.N. sanctions to sell such devices to Saddam Hussein's regime.

"We have noticed some attempts by the Iraqis to use a GPS jamming system that they obtained from another nation. We have destroyed all six of those jammers in the last two nights' airstrikes. I'm pleased to say they had no effect on us," said Air Force Maj. Gen. Victor Renuart.

U.S. forces were "on track" in the drive toward Baghdad despite sandstorms that enveloped troops on the battlefield Tuesday, he said.

"The dark days are probably coming for the dark side, and Saddam's regime has more dark days ahead than we do," Renuart said.

U.S. forces were "maintaining and increasing pressure on all fronts, even in the bad weather," he said.

"It's a little bit ugly out there today," Renuart said. "Weather has had an impact -- wind, rain, thunderstorms. It's not been a terribly comfortable day on the battlefield. However, that hasn't stopped us."

Brig. Gen. Vincent Brooks showed video of U.S. forces parachuting into Iraq and taking a desert airstrip in an undisclosed location. He also said Iraqi forces had been hiding weapons next to civilian buildings and displayed pictures of a water treatment plant with an anti-aircraft missile battery located next to it. He said the missiles were destroyed without damage to the plant.

He also pointed out on an intelligence photo that Iraq had hidden a MiG fighter in a cemetery next to an airfield.

Renuart warned Iraqi civilians to stay away from military formations and buildings used by Saddam's regime and its leaders. He also advised them to keep off the roads to limit casualties.

"It's very difficult to guarantee their safety on this battlefield," Renuart said.

"I continue to remind the people of Iraq that the battlefield extends across the country now," he said. "We have forces in all areas of the country. It's not really safe for Iraqis to drive, to try to flee danger. It's really much safer for them to remain in their houses."

Asked about Iraqi casualties, including children who had been hospitalized as a result of U.S. attacks, Renuart said: "It is a tragedy to see the children that are injured."

"Warfare, even its most precise fashion, is not absolute. There are errors that occur," he said.

Renuart said coalition forces were building prisoner of war camps for the Iraqi prisoners which U.S. officials have estimated to number more than 3,000.

He said the International Committee of the Red Cross would have full access to the camps.

Renuart said Marines fighting Iraqi army and Saddam Fedayeen militia around the southern city of An Nasiriyah "did suffer some casualties," but he refused to give numbers or other details until families were told.

"I'd like to not confirm numbers because we are still assuring that proper notification has been done," Renuart said.

He also could not be specific about Iraqi killed or wounded.

"I really could not tell you. A lot of our airstrikes are in places we don't not have military forces to actually do that kind of accounting work so it would be unfair of me to make any assessment of Iraqi casualties."

Renuart said key targets on the battlefield were surface-to-surface missiles and the Iraqi elite troops of the Republican Guard.

Asked about weapons of mass destruction, he said coalition forces were checking a number of sites that had been the subject of concern in the past, but there had been no confirmation of banned weapons having been found.

"We continue to interview key leaders we've detained on the battlefield and we're developing that information to lead us to more sites," he said.

Coalition forces reported that Iraqis have begun igniting huge trenches filled with oil outside Baghdad, sending up plumes of black smoke.

"Unfortunately, this shows the regime is very willing to destroy its own resources to protect itself," Brooks said.

Renuart accused Iraqi forces, especially the Fedayeen militia, of "terrorizing neighborhoods" and using civilians as human shields.

"Human shields are a cowardly way to act on the battlefield," Renuart said. "I'm comfortable that we will not put our troops in the position where we would disregard the safety of any noncombatants."