Camels are led past U.S. Marines with the 15th  Expeditionary unit, Echo Company, at a checkpoint in the  southern Iraqi city of Nasiriyah, Saturday, April 12, 2003.  (AP Photo/Itsuo Inouye)

CAMP AS SAYLIYAH, Qatar - U.S. Marines were operating Sunday near the dusty desert town of Tikrit, a power center for Iraq's Sunni Muslim tribes that is believed to be the one of the last strongholds of fighters loyal to President Saddam Hussein, U.S. Central Command said. A task force from the 1st Marine Expeditionary Force was within about 35 miles of the town, approaching from the south, having "moved north along Highway 1 to Tikrit from Samarra," said Lt. Mark Kitchens, a Central Command spokesman. Named Task Force Tripoli, it includes several regimental combat teams and light-armor reconnaissance battalions.  "It's still unknown how much resistance awaits coalition forces in Tikrit," Kitchens said.

U.S. officials have played down the prospect of a major battle in Saddam's hometown because of desertions and damage from repeated airstrikes. The first TV news footage of Tikrit, aired live Sunday by CNN, indicated its northern defenses had been weakened, but the CNN crew fled after coming under fire. 

Kitchens said the Marines were operating "in the vicinity of Tikrit" but he refused say how close they were to the city itself, or whether troops had entered it or its outskirts. 

He said the Marines' orders were to push forward, move north, and if they engage any enemy forces "to attack those forces and eliminate them." 

He didn't say if there had been any significant fighting on the road from Baghdad. Tikrit is about 90 miles north of the Iraqi capital. 

The live report by CNN suggested intense U.S. airstrikes had taken a heavy toll on the Tikrit's military forces. However, the convoy of CNN vehicles came under small-arms fire as they tried to enter the city center. A CNN security guard returned fire at least twice, and the news crew quickly drove away. 

Two members of the CNN party were injured, according to Eli Flournoy, CNN's senior international assignment editor. He said an Iraqi Kurd serving as a security guard was grazed by a bullet, and a CNN producer was hit by shattered glass. 

Before the shooting, CNN correspondent Brent Sadler had reported that U.S. military officers were negotiating with tribal chiefs in Tikrit for a peaceful surrender of the city. But after the gunfire, he said Saddam's loyalists in Tikrit were "clearly still in control." 

As Sadler described the unfolding situation, gunfire was visible hitting the road ahead of them, kicking up dust. "That was a pretty ugly moment," Sadler said. "I have never come under such direct fire." 

Central Command spokesman Capt. Stewart Upton said he had no reports of any surrender negotiations with any remnant fighters in the city. 

Upton said troop movement north from Baghdad was "extremely fast." 

Further north, in the city of Mosul, a U.S. Special Forces soldier was shot and wounded Sunday while on a patrol aimed at improving security. 

Maj. Fred Dummar said the soldier was in a Land Rover, driving past a waving crowd, when a bullet smashed through the rear window and struck his leg. The wound was not believed to be life-threatening, but it was expected the soldier would be evacuated to Germany for further treatment.