FALLUJA, Iraq (Reuters) - U.S. Marines were conducting painstaking weapons searches in the Iraqi city of Falluja on Monday when they spotted a man with an AK-47 rifle on a nearby rooftop.
Armed only with a light weapon, he could never stand up to what they were about to unleash. But he was enough to distract Marines from a task that is key to stabilizing Falluja after a U.S.-led offensive crushed rebels controlling the Sunni Muslim city.
The angle of the rooftop could not quite accommodate the trajectory of a shoulder-launched Javelin missile so Marines fired the more direct, wire-guided TOW missile after a debate.
Then they fired hefty .50 caliber machinegun rounds at the rooftop, blew up a door and stormed a living room. It was an impressive display of firepower but they raided the wrong house.
When they finally made it to the pulverized rooftop with smoke still rising from the machinegun bullet holes, the man with one rifle they were seeking had escaped.
"One of the main challenges we are facing in conducting weapons searches is these lone snipers who randomly appear and delay our operations," said 1st Lieutenant Christopher Wilkins, 24, as he led a weapons hunt in central Falluja.
At that point, his platoon had only found a few sacks with AK-47s, some hand grenades, an artillery shell and, most notably, a pick-up truck mounted with surface-to-air missiles.
After pounding Falluja with air strikes, artillery fire and tank shells, Marines are now scrambling to find caches so that some 300,000 residents who fled before the assault can return.
They have been astounded by the quantity and variety of weapons, from Egyptian submachineguns to Russian and German models and flame-throwing rifles.
Hundreds of mortars, rocket-propelled grenades, rocket launchers and bomb-making equipment have been uncovered inside couches, behind hidden walls and even on top of the city water tower, Marine officers said.
Marine officers say they know tracking down all insurgents is impossible but they hope the weapons searches will lead them to houses that guerrillas could use in future.
Some insurgents are still keen to fight.
A few were caught swimming across the Euphrates river to get back into Falluja at a spot near the hospital, holding up their AK-47s above the water and floating on beach balls, Marine officers said.
"This could take weeks and even months to make Falluja safe for its people to return," said Lieutenant Colonel Larry Kling.
Marines, who expect to stay in Falluja until Iraqi forces can take over security, can't afford to push too hard or fast in the house to house searches because they are trying to gain the trust of residents.
Falluja's people might already have reason for anger. The offensive has reduced many parts of the city to rubble.
But Marines searched aggressively in a middle class neighborhood; behind paintings, in couches and even toy boxes.
"I tell my men not to be too aggressive so that people will not have more hatred when they come home," said Wilkins. "But the problem is these weapons are hidden in incredible places."
Marines search between 20 and 50 houses a day and 80 percent of them have weapons hidden inside. Some had time to joke despite the risky and sensitive challenge ahead.
Standing over a crater six meters (20 ft) across and six meters deep in a street created by what he said was a 2,000- pound bomb during the offensive, Staff Sargeant Jonathan Knarth, 29, of Florida, looked at down the deep water at the bottom.
"Hey look all you have to do is extend a slide from that rooftop to the water and you have an amusement park right here courtesy of the United States Air Force."