With warplanes patrolling the skies over Baghdad, U.S. troops made their second show-of-force foray into the Iraqi capital. Meanwhile, British troops have staged their largest incursion in Iraq's second largest city, Basra.

Powerful explosions were heard in Baghdad, as U.S. troops made their second incursion into the Iraqi capital.

Brigadier General Vincent Brooks described U.S. casualties as light in a previous confrontation Saturday on the southern outskirts of Baghdad. But he said an estimate of 2,000-3,000 Iraqi deaths was reasonable.

"We know it was a considerable amount of destruction on all of the force that was encountered. And so I have tried to characterize it in those types of terms, 'a considerable amount of destruction.' In virtually every engagement we have, it is very one-sided," Gen. Brooks said.

VOA Correspondent Alisha Ryu, who is with U.S. forces at the Baghdad Airport, said she believes Saturday's show of force was aimed at sending a message to the Iraqi regime. "I think that was more of a symbolic gesture Saturday, just to let the Iraqis know that they could move in at any time. And I think it was a lot to do with Iraqi claims that the U.S. and coalition were nowhere near the capital," she said.

In the south, a column of British tanks and armored personnel carriers rumbled into Basra, to root out paramilitaries still holed up there.

Royal Air Force Group Captain Al Lockwood says local civilians have been providing British forces with some assistance. "Literally, getting into our armored vehicles, going into the city, sort of probing into areas where we have not been before, checking to see what the response from local civilians is, but, more importantly, looking for these paramilitary forces that we know are in there, trying to seek their hideouts, using the information that local people have given us to go in there and try to get them out of there, and away from the local population," Captain Lockwood said.

In northern Iraq, Central Command said it is investigating a report of "friendly fire." A British journalist who witnessed the incident said a U.S. warplane bombed a Kurdish convoy escorted by U.S. special forces, killing a number of people.

Meanwhile, Russia said a convoy of Russian diplomats was fired on Sunday as it left Baghdad, bound for Syria. It is not clear who fired at the convoy.

In Washington, Deputy Defense Secretary Paul Wolfowitz told Fox News Sunday he is not concerned that coalition forces have not yet found indications of weapons of mass destruction. "The key to finding these things is to get the people who know about it in circumstances where they are no longer fearful, intimidated and let them tell us. And we are not at that point. In fact, most of those people are probably collected in places where they are intimidated and terrorized," Mr. Wolfowitz said.

Mr. Wolfowitz added that the top priorities for coalition troops on the ground is winning the war, getting control of the country and toppling, what he called, Iraq's evil regime.