As US Marines have blasted their way through Fallujah, another insurgent outpost has grown stronger 48km down the road in Ramadi.
Insurgent attacks on US troops here have markedly intensified in the past two weeks, and enemy combatants are now conducting a more determined battle, commanders say.
"My personal take is that Ramadi is a less-publicized Fallujah, in the sense of the combat you face every time you go into town," said Captain Ben Siebold, a company commander in an Army battalion stationed downtown at a small and aptly named base, Combat Outpost.
"In the time I've been here, the nature of the enemy has changed," he said. "He's more determined, more organized and a little bit better shot."
It is a daily struggle, with insurgents burying powerful remote-controlled explosives on roadsides as quickly as US bomb squads can remove them. Some mosques, meanwhile, have turned into ammo dumps for insurgents who flee to them after taking shots at US convoys with rocket-propelled grenades and mortars.
In the latest example, US troops on Saturday raided the largest mosque in Ramadi after troops took fire from gunmen inside. Soldiers found hidden in air ducts two Kalashnikov rifles and 18 magazines for the weapons, along with anti-US propaganda.
Inside the huge building, Private Frist-Class Jeffrey Moore of Felicity, Ohio, tucked a handgun into his belt and shinnied up a 12m-high ventilation shaft looking for weapons.
On the roof, about 20 soldiers looked through rifle scopes at suspected insurgents near another mosque about 500m away.
Shortly before 3pm, a driver on the road below ignored repeated warning shots and sped toward the mosque. The troops, suspecting a suicide bomber, fired hundreds of rounds at the car, killing the driver.
After the car was engulfed in flames, several secondary explosions were heard; soldiers said one could have been triggered by armaments inside.
According to commanders in Ramadi, the heightened violence here is an outgrowth of the siege of Fallujah and the holy fasting month of Ramadan. They say some insurgent fighters from Fallujah have migrated to Ramadi, a city of 400,000 on the Euphrates that is the capital of sprawling Anbar province, which covers most of western Iraq.