The marines attacked the mosque and a presidential palace complex around the Tigris river in central Baghdad after receiving a tip-off that the Iraqi president was inside, said Major Rod Legowski, liaison officer of the 3rd Infantry Division (3ID).

"That's what we were told. That's why we went after those targets -- Saddam and other top level officials," Legowski told reporters.

"I cannot confirm whether he was actually there ... There was significant military value to those targets and it was successful."

One US marine was killed and 20 wounded in the exchanges of fire, he added.

Witnesses said five Iraqis were also killed and six wounded in the firefight with US marines close to Adhamiya mosque.

The marines were under fire since 2:00 am (2200 GMT on Wednesday) from fighters hiding in civilian areas, in buildings, cars, behind lines of laundry on rooftops and beneath bridges, an AFP correspondent on the ground saw.

Iraqi fighters used AK-47s and rocket-propelled grenades (RPGs), the correspondent said.

Legowski said it had taken four-and-a-half hours for the marines to bring the situation "under control". He could not say whether they entered or hit the mosque.

US tanks and M16 mortars were used in the operation while fixed wing aircraft flew overhead, he added.

"It's a show of force, we can go where we want," said First Sergeant Jeff Treiber, adding that artillery fire could be heard outside the walls of Saddam Hussein's Adhamiyah palace.

Major Pete Farnum also said a nearby mosque had been secured.

"There were intelligence reports the mosque was a Saddam stronghold," Farnum said, describing the mosque as being close to the northern banks of the Tigris.

"We displayed our ability to impose our will," he said, in reference to the marines capturing the mosque and palace.

The palace complex resembled a huge art-deco movie theatre with giant stone towers and marble tiles.

It consisted of three palaces, one of them dome-styled that had been bombed. Heaps of rubble lay all around as huge antique sofas and Ottoman-style chairs with gold lace hung out of the debris.

A total of 22 POWs were taken from the mosque to the palace, according to Private Matthew Sienkiewicz, who among other marines, found the 22 men in the mosque basement and arrested them.

"Some of them were Egyptians," said Sienkiewicz, 20, with the Alpha Company.

"They were telling us 'Cairo, Cairo'. They said they did not love Saddam but they had Kalashnikovs and RPGs," Sienkiewicz said.

When marines arrived at the mosque, where they waited for an hour before moving in, they came under heavy fire with at least one assault vehicle being hit three times by rocket-propelled grenades while two others fell short of the vehicle.

Corporal Luke Mondoux said the inside of the mosque compound "looked like military barracks, there were lockers and mattresses."

Outside the compound, Iraqi fighters drove by trying to fire RPGs over the wall at the marines, during which at least four Iraqis were shot.

At one point, marines from the Tracks Company patrolled a neighbourhood where they believe Saddam and one of his sons were hiding when they came under ambush along a small alley, the AFP correspondent said.

A heavy volley of Kalashnikov fire ensued and the marines received two rocket-propelled grenades, leaving one marine with shrapnel wounds to the face, bleeding all over the vehicle. He was later evacuated.

"It's a dirty job but it's part of it," said 23-year-old Corporal Michael Sonne, amid the thundering explosions.

"It was a never ending drive," Battalion Gunner David Bednarcik said of the heavy fighting.

One marine who lost his comrade said they had been ambushed on a road.

"Humvees don't protect us in a fight," said the unidentified marine, who had been riding in a soft-top Humvee all-terrain vehicle when attacked and the marine was killed.

SPACE.WIRE