The men from the second battalion of the 7th Cavalry Regiment received the order at midnight Tuesday (2100 GMT) to secure the eastern side of two bridges over the Euphrates.

They had already been seized a day earlier, when the offensive dubbed Operation Dawn was first launched, along with the main hospital.

Eleven hours later Karcher and his troops were rumbling in their Humvees and Bradley armoured fighting vehicles down the main east-west road that cuts through the rebel city and forks into the two bridges.

They took control of the southern bridge first. A few hours later they secured the one further north.

They were worried that insurgents may have booby-trapped the bridges. An ordnance team swept the area, but found nothing.

The war for these men started with the takeover of the railway tracks on the northern fringes of the city on Monday at 10:00 pm.

They then started penetrating the city after two sidestreets leading into the main road were blasted clear of bombs planted by the rebels.

They drove down a road that runs next to the cemetery and then headed south into the Jolan district, considered Fallujah's main insurgent stronghold.

"There was very, very little organised resistance," Karcher said.

"Our aim was to make a deep penetration into enemy lines and let the marines do the search for the enemy."

On Tuesday at 6:00 am they arrived an open park area in Jolan. They had to wait there for marines who were coming on foot behind them.

An hour later their unit was attacked.

"Some insurgents were not bad, but they came at us in an unorganised manner" said Karcher.

At 12:00 pm they secured the area.

Going further south they reached an industrial site near the martyrs' cemetery in the centre.

After air strikes on the area, tanks came into action.

He said they met little resistance here too, but that it took some time to clear up the area and search it room by room.

He said 25 to 30 insurgents were killed in the area out of a total of 70 to 80 killed that day.

The 7th Cavalry was created in 1866 and it took part in General George Custer's debacle at the Battle of the Little Bighorn.

The battle also called Custer's last stand was an engagement between a Lakota-Cheyenne combined force and the 7th Cavalry in 1876 near the Little Bighorn River in the eastern Montana Territory.

The battle was the most famous incident in the Indian Wars and was a crushing victory for the Lakota and their allies. The US cavalry detachment commanded by Custer was killed to the last man.

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