"He knows he is losing the south as we get stronger in Nasiriya, so he is trying to shore up his resistance, to keep those loyal to Saddam enlisted -- the Fedayeen and the Iraqi army," the source said. 

Meanwhile, U.S. forces continued operations in and around Nasiriya, where fighting first erupted eight days ago. 

C-130 flying gunships overnight blasted areas of the city believed to contain snipers and Saddam Fedayeen fighters, and the 2nd Marine Light Armored Reconnaissance unit targeted several apartment buildings on the north bank of the Euphrates River. 

Pointing to one building, a Marine said, "They keep coming back to that building after we have blown the place apart. There must be something in there they want pretty bad." 

In areas around Nasiriya, civilians told CNN they had been terrorized for years by Baath Party operatives. 

One Iraqi, who goes by the name Hayat, said through an interpreter that Baath Party "thugs" shot him three times and left him for dead when he refused to fight in the Persian Gulf War. He said he has been trying to eke out a living between subsistence farming and odd jobs since to support his wife and three children. 

Baath Party members come by all neighborhoods in Nasiriya on a regular basis to extort money and test loyalty, Hayat said. If neither is forthcoming, he said, "You will be shot." 

Marine officers said they hope to expedite the Iraqi regime's collapse by reaching civilians such as Hayat through humanitarian programs and displays of goodwill. U.S. forces also are trying to enlist tribal leaders to join the U.S.-led coalition and help keep Saddam's forces at bay. 

"If we can pass the word at Nasiriya and the tribal leaders pick up on it, we are halfway home," one Marine said.