Iraqi troops fought U.S. forces overnight near the central Shi'ite city of Najaf as American bombs again shook Baghdad, briefly knocking out parts of the power grid. Just as the call to dawn prayers was sounding in the Iraqi capital, one particularly strong blast shook the city center as planes rumbled overhead, Reuters correspondent Samia Nakhoul said. Overall, the rhythm of the overnight bombing was sporadic.

Reuters correspondent Luke Baker, traveling with units of the U.S. 3rd Infantry Division, saw a limited clash with Iraqi troops 45 miles southeast of Najaf that held up the U.S. advance overnight.

U.S. officers told him there was heavier fighting barring the way further upriver, close to Najaf itself, which is just 100 miles south of the capital.

The Iraqi authorities also reported a battle in the desert near Najaf, an important religious center for the Shi'ite Muslim majority on the western bank of the Euphrates River.

Some U.S. advance columns have covered about two thirds of the 300 miles of the distance to Baghdad in two days since they and their British allies poured over the Kuwaiti border in an invasion to oust President Saddam Hussein.

Najaf is the closest major ground fighting to the capital, which suffered another night of bombing, though nothing like the pounding it took the previous night. A Reuter's correspondent also saw an air raid on the northern city of Mosul.

CLASH AT NAJAF

Iraq's ruling party said in a broadcast statement that U.S. forces had fled after a desert clash near the city, on the west bank of the Euphrates. The local leader of President Saddam Hussein's Baath party was killed in the fighting, it added.

Speaking at about 3.00 a.m. from a point some 45 miles southeast of Najaf, Baker said the U.S. unit he was with was held up but officers were confident of moving on toward the city where other U.S. units were meeting stiffer resistance.

U.S. commanders believe a division of Saddam's better-equipped Republican Guard was in place at Najaf.

"U.S. officers say the tanks and armored infantry up ahead are involved in what they call 'small-scale enemy contact'," Baker said. "I've seen a couple of what look like muzzle flashes from tanks, but no incoming shells."

The U.S. military says it has secured a bridge across the Euphrates at the city of Nassiriya, 235 miles southeast of Baghdad. But Iraq's information minister said on Sunday that its forces were still putting up resistance around Nassiriya.

Reuter's correspondent Andrew Gray, with the 3rd Infantry, said a battle raged on Saturday for an airfield near Nassiriya.

U.S. Marines, who bypassed colleagues fighting around the main southern city of Basra, were poised to strike north toward Baghdad. An arduous desert trek had put them astride the main Baghdad highway north of Basra, Reuter's correspondent Sean Maguire, who is with the Marines, said on Saturday.

FOCUS ON BASRA

Al-Jazeera television, quoting Iraqi medics, said 50 people were killed when U.S. F-16 planes bombed near Basra.

Raw video footage, beamed across the Arab world by the Qatar-based satellite channel, showed a child with half its head blown off. It was unclear if it was a boy or a girl.

"It's a huge mass of civilians," one angry woman told al-Jazeera, standing among the wounded. "It was a massacre."

The report could not be independently confirmed. U.S. officials declined to say whether their planes had bombed Basra.

A U.S. officer said earlier that Marines defeated Iraqi forces in a battle on the outskirts of Basra on Saturday, taking many prisoners, but it was not clear who controlled the city.

In the north, Reuter's correspondent Sebastian Alison saw anti-aircraft fire and explosions around midnight at Mosul, which had been hit by air raids a day earlier. He was watching from Kurdish-held territory 25 miles away.

In Baghdad, the information minister said several houses were hit. Reuter's correspondents watched and listened as fresh raids hit the capital, briefly knocking out some power.

The Iraqi government said three people died and 207 civilians wounded in heavy bombing on Friday and into Saturday.

Iraqi forces set oil-filled trenches ablaze around the capital in an apparent bid to create a smokescreen. Some of the weekend raids were not met with anti-aircraft fire.

PHOTO CAPTION

Iraqi troops fought U.S. forces early March 23, 2003 near the central Shi'ite city of Najaf as American bombs again shook Baghdad, briefly knocking out parts of the power grid. (Reuters Graphic)