BAGHDAD — Thousands of U.S. and Iraqi troops fanned out across the fields of southern Iraq in scorching temperatures today as the military said it remained determined to find two missing U.S. soldiers after the body of a third was pulled from a river.

Also today, a car bomb targeting a funeral procession in the turbulent city of Fallujah killed at least 21 people, police and medical officials said.

The military confirmed today that the body found a day earlier in the Euphrates River south of Baghdad was that of Pfc. Joseph Anzack Jr., who had been missing since militants ambushed his unit nearly two weeks ago.

A commanding officer identified the remains recovered from the river, but DNA tests were still pending, military officials told Anzack's family.

"They told us, 'We're sorry to inform you the body we found has been identified as Joe,"' the soldier's aunt, Debbie Anzack, said Wednesday. "I'm in disbelief."

Anzack, 20, vanished along with the two other soldiers after their combat team was ambushed May 12 about 20 miles outside Baghdad. Five others, including an Iraqi, were killed in the ambush, subsequently claimed by al-Qaida.

"We can confirm that we have recovered the remains of Pfc. Anzack," Lt. Col. Josslyn Aberle, a military spokeswoman, said today.

The attack triggered a massive search operation in the area south of Baghdad known as the triangle of death for the insurgent activity there.

Today, soldiers proceeded with their mission, despite Anzack's death. One unit searched chicken coops and trudged through mud, canals and tall reeds in the brutal heat.

"The search continues," said Lt. Col. Christopher Garver, a U.S. military spokesman.

Members of Anzack's platoon choked back tears at news of his death and said they would not stop looking for the other two missing soldiers.

"We can't leave them behind. I just hope that they have enough faith to keep them going. What they're going through right now, I can't imagine," said Pfc. Sammy Rhodes, 25, of Albuquerque, N.M.

Spc. Daniel Seitz, 22, from Pensacola, Fla., said he was trying to stay strong and push ahead with the search.

"It just angers me that it's just another friend I've got to lose and deal with, because I've already lost 13 friends since I've been here and I don't know if I can take any more of this," he said.

Aberle denied reports that a second body had been found and was being examined to determine if it was that of another of the missing soldiers. "The reports of a second set of remains being found is a false report," she said.

The U.S. military also announced today that two U.S. soldiers were killed the day before while conducting combat operations in Iraq's volatile Anbar Province. Those deaths, along with the deaths of nine other troopers announced Wednesday, brought the American death toll for the month to at least 82. Last month, 104 U.S. troops were killed in Iraq.

The increase in U.S. deaths come at a difficult moment for Washington, where the administration of President Bush and Congress are struggling to agree on funding for the unpopular war. The search for the captured soldiers has also taken thousands of troops out of the pool of forces for the Baghdad security crackdown.

In other violence, a parked car bomb exploded this morning in Fallujah as a funeral procession passed by for a man who worked against al-Qaida in Iraq.

The blast killed 21 people and wounded 50 others, police and medical officials said. The funeral was being held for Alaa Zuwaid, a 60-year-old restaurant owner who was part of a tribe that had formed an alliance with other tribal leaders against al-Qaida.