Pfc. John Alonzo knew Christmas would be his toughest time in Iraq.

"Ever since I volunteered, I haven't been looking forward to it," said the 27-year-old, from Lubbock, Texas. "My son wants to know why I can't be home for the holidays. He doesn't understand that I can't just quit."

Before dawn on Sunday, Alonzo and the rest of the 5th Battalion, 20th Infantry Regiment rolled through muddy, unpaved streets in a volatile corner of east Baghdad, hunting house-to-house for Shiite militia leaders and bomb-making materials.

Although they did not know it, a roadside bomb in the same neighborhood had killed three U.S. soldiers the day before; a fourth died in an explosion in Diyala province east of the Iraqi capital.

As the sun came up over the city Sunday, a soldier sang "Silver Bells" while others smashed windows in a tall residential apartment building to get a better look at the street below. "It's Christmastime in the city," he crooned.

A mortar round landed in the area. Later, a rooftop sniper fired a single shot that penetrated the helmet of a U.S. soldier, grazing his head. The lightly injured soldier was treated at his base camp.

The troops will spend Christmas raiding another section of the city.

"It's hard. But we've still got work to do. The mission doesn't stop," said Alonzo, who left his job as a beer salesman and enlisted because the Army provided better health care benefits for his three small children, and money for his wife to finish college.

There are small signs of the season across Iraq, where thoughts of the friends and loved ones they miss weigh heavier than usual on the minds of U.S. troops. But for most, Christmas is just another day.

"In the back of your mind you think about it, but there are no holidays in Iraq," said Staff Sgt. Brandon Scott, a 35-year-old from Woodbridge, Va., and the 5th Battalion, 20th Infantry Regiment, which is part of the Army's 3rd Stryker Brigade Combat Team, 2nd Infantry Division.

A 16-year veteran of the Army, Scott said he was spending his third Christmas in four years away from his four children. "We don't really have time for Christmas," he said.

But that doesn't mean there aren't gifts.

Care packages stuffed with cookies, candy canes and Christmas cards penned by children from coast to coast have flooded every U.S. military outpost across the country. Often sent by strangers looking to support the soldiers any way they can, there are more sweets than the troops can eat and enough bottles of shampoo and batteries, used paperbacks and cans of peanuts to get them through the next decade. A single package from California to Forward Operating Base Liberty in Baghdad contained no less than eight MP-3 players.

Capt. Samuel Fuller, a 29-year-old Chicago native, said his wife arranged to send a small present for every member in his 72-soldier company.

"Our leadership is trying to pull guard shifts so that some of the soldiers can rest and call their families. Maybe smoke a cigar," Fuller said. "But it's hard to find time to relax."

Asked what he wanted for Christmas, Fuller's thoughts turned to roadside bombs known to soldiers as Improvised Explosive Devices.

"A day without IEDs. Definitely that'd be the best," said Fuller, part of Company A of the 2nd Infantry Brigade Combat Team's Special Troop Battalion, which spends its days searching for explosives on Baghdad's streets.

At an Army outpost in Ramadi, the most-dangerous city in insurgent-dominated Anbar province west of Baghdad, soldiers decorated a full-size artificial Christmas tree with mines, smoke grenades and machine gun rounds and stuck a massive knife on the top.

"You can go anywhere in Iraq," grinned Staff Sgt. Jeremy Gann, a 24-year-old from Dallas, Georgia, who is part of the 1st Battalion, 37th Armor Regiment. "You won't find another Christmas tree like it."

He is right, but there are other, less violent signs of Christmas.

An inflatable snowman too tall for the low ceiling guards the hallway of the headquarters building at camp Liberty, and soldiers stuck a small pair of red-and-green, plastic reindeer antlers on the front of one of the Stryker vehicles they ride to missions.

Curled up in a camouflage sleeping bag on a green cot inside a former prison where some soldiers at Liberty sleep, 1st Lt. Sean McCaffrey put on a red Santa's cap and smiled.

"This probably won't be too good outside with the snipers," said McCaffrey, who affixed a small plastic Christmas tree to the cot of a neighbor.

On a recent patrol, Staff Sgt. Anthony Handly said he saw evidence of Baghdad's small Christian community.

"There was actually a store selling plastic Christmas trees," said Handly, 30, of Bellingham, Wash. "I guess someone in Baghdad is celebrating it."

McCaffrey and Handly are part of the 5th Battalion, 20th Infantry Regiment, just like Alonzo, who said his family purchased an artificial tree for the first time this year, because he wasn't around to pick out and decorate a live one.

"My daughter asked if they could just keep the tree up until I get home on leave in February," Alonzo said smiling. "We'll see if they do that."