M1-A1 Abrams tanks, Bradley fighting vehicles, and armored Humvees took to Ramadi streets as soldiers patrolled streets searching for weapons and militants, Stars and Stripes news reported Monday.
Shops were closed and most residents stayed indoors, officials said.
Claims that insurgents dominate Ramadi in much the same way that they do in Fallujah are not accurate, said Col. David Clark, commander of the 1st Battalion, 506th Infantry Regiment.
"There had been relatively heavy fighting in there for a day or two before," he told Stars and Strikes. "We moved in to try to get the city back under control, re-establish a presence and provide the protection to keep the government firmly in control.
"We don't want this to turn into another Fallujah, which is what we think the bad guys are trying to do."