Updated

In his calls and notes from Iraq, Army Pfc. Kristian Menchaca told relatives about his dangerous assignment at military checkpoints.

His family is now hoping for the 23-year-old Houston soldier's safe return after learning he was one of two servicemen missing in Iraq after an insurgent attack.

An umbrella group that includes al-Qaida in Iraq claimed in a statement Monday that it had kidnapped the two U.S. soldiers, but it did not name them. There was no immediate confirmation that the statement was credible, although it appeared on a Web site often used by al-Qaida-linked groups.

"I was 95 percent sure he was one of them," Menchaca's brother, Julio Cesar Vasquez, of Houston, told The Associated Press late Sunday. "I already had an idea because he was at a checkpoint."

U.S. officials said they were still trying to confirm whether the missing soldiers were kidnapped during the attack Friday on their checkpoint south of Baghdad.

White House spokesman Tony Snow, speaking with reporters aboard Air Force One, said President Bush was being briefed regularly on the missing soldiers. Snow said "an al-Qaida related group has today issued something claiming responsibility, but there's no confirmation."

The military has said soldiers nearby heard small-arms fire and explosions, and a quick-reaction force reached the scene within 15 minutes. The force found one soldier dead but no signs of the other two. A farmer told the AP that two soldiers had been captured by seven masked gunmen.

Vasquez and other members of Menchaca's family said they were waiting for more information as the military searches for Menchaca and Army Pfc. Thomas Lowell Tucker, 25, of Madras, Ore.

The Defense Department said Spc. David J. Babineau, 25, of Springfield, Mass., was killed in the attack. All three soldiers were assigned to Fort Campbell, Ky.

Kay Fristad, an Oregon National Guard spokeswoman, said she had a brief conversation with Tucker's parents and they said he joined the military "to do something positive for the country."

Fristad said Tucker's family had been camping this weekend and only recently learned the news. She said they have asked for privacy and would not comment until Monday.

Former Madras Mayor Rick Allen, whom Tucker worked for at a gas station while he was a student at Madras High School, described Tucker as strong, street smart and mechanically inclined.

"He's a tough kid. Hopefully he's got the inner strength to make it through this ordeal."

Allen said he learned the news on television.

"It's just bizarre; it takes your breath away. Here's this kid who used to come and pump gas at your place and now he is clear across the world -- held," Allen said. "And there's nothing anyone can do, except hope these people have compassion and let him go."

Menchaca's wife, 18-year-old Christina Menchaca, of Big Spring, Texas, said military representatives told her Saturday they were taking "every means possible to find him," she said.

"We're basically just watching the news because no one else knows anything about it, no one has heard anything about it," she said. "We're just going by what the news has to say."

Christina Menchaca said she married her husband in September and he deployed in October. The couple met through her brother, who served in the military with Kristian Menchaca.

"He enjoys being in the military," Christina Menchaca said of her husband, from whom she received an e-mail on Tuesday. "That's basically what he wants to do."

Kristian Menchaca's mother, Maria Vasquez of Brownsville, Texas, said she last heard from her son a few weeks ago. Along with asking for some treats from home, like Cheetos and cleaning wipes, the soldier told his mother he was working at a checkpoint.

"I'm a little bit nervous, and I cannot sleep," she said. "I worry about him."

Julio Vasquez said his brother joined the military last year and deployed to Iraq within months. He was attending a work-force training center when the Army recruited him.

"He wanted to go infantry," Julio Vasquez said. "We were telling him the dangers that infantrymen had, but that's what he wanted to do."