"We were on some very exposed ground and we didn't get anyone," said an exhausted Lance Corporal Migel Nunez, 22, of Elgin, Texas.
It was their tenth ambush mission in Iraq, none of which killed or captured a fighter near the city, site of a weeks-long standoff with resistance fighters who the US occupation forces say include Saddam Hussein loyalists and foreign Muslim fighters.
For weeks US Marines operating near the city have been searching houses, hunting suspected fighters and setting up ambush positions deep in enemy territory.
But the operations have yielded few tangible results and despite their high-tech weapons and draconian discipline, US Marines are struggling against resourceful resistance fighters with no clear leadership, structure or supply lines.
Marines say the fighters have mastered the art of attacking them and then melting away in villages where it is impossible to distinguish between fighters and civilians.
"It is just impossible to tell them apart. They can't aim very well and they don't have lots of weapons but they are resourceful and smart. They are geting better"
"They fire their AK-47s from their homes, walk out the back door and then actually walk up and shake hands with American soldiers when the fighting is over," said Lance Corporal Peter Johnson, 20, of Wheaton, Illinois.
"It is just impossible to tell them apart. They can't aim very well and they don't have lots of weapons but they are resourceful and smart. They are getting better."
Signs of activity
That reality is especially troubling for Marines who had hoped to launch an offensive in besieged Falluja but have instead been searching for resistance fighters in nearby villages along roads infested with bombs.
So far they have seen signs of activity only in hamlets where assault rifles are hidden in wheat fields, while they listen to air strikes and explosions around Falluja in the distance.
Some Marines have begun questioning their own tactics. Many complain they alert their enemies long before they enter villages by travelling in noisy armoured vehicles.
Some Marines have begun
questioning their own tactics
But commanders say moving in small groups is far too risky in a land where everyone from farmers to soda shop owners could be guerrilla supporters or fighters.
Overnight on Thursday, the sniper unit attached to Golf Company returned to a village they left just hours earlier, hoping to ambush fighters who might have returned.
As soon as their noisy armoured vehicle approached, every household in one hamlet turned off its lights and then switched them on again when they left, an apparent signal to fighters.
'They know everything'
"The problem is they know everything about us. They hear us coming, they know what vehicles we ride in and calculate how many in each vehicle," said Private First Class Joseph France, 19, of Batesville, Indiana.
"We know nothing about them. We don't know who they are. They know how to surprise us and they are resourceful with their weapons and know how to escape."
"They hear us coming, they know what vehicles we ride in and calculate how many in each vehicle"
Private First Class
Marines recalled how one resistance unit put ice in a mortar tube and then pumped the mortar down it. The ice melted and the round was fired after they made their getaway.
The eagerness to kill fighters showed in a recent skirmish when Marines entering a village spotted three men running as they approached. They pursued and fired on the men, killing one, wounding and capturing another.
Marines said the men fired on them. A senior officer said they had no weapons, but that with shots coming in the men were legitimate targets because they ran.