BAGHDAD - Roadside bombings and gunbattles across Iraq killed nine U.S. servicemen, and U.S. authorities were examining a body found in a river south of Baghdad that Iraqi police believe is one of three U.S. soldiers seized in an ambush nearly two weeks ago, officials said today.

U.S. authorities have not determined if the body found in the Euphrates River was one of three missing American soldiers from the May 12 ambush of their patrol near Mahmoudiya, about 20 miles south of Baghdad. Four Americans and one Iraqi soldier were killed in that attack.

The military said seven soldiers and two Marines were killed in separate attacks Tuesday, bring the U.S. death toll for the month to at least 80. Last month, 104 U.S. troops were killed in Iraq.

U.S. officials have warned that American casualties were likely to increase as troops made more frequent patrols during the three-month-old U.S.-led security crackdown in Baghdad.

Six of the soldiers were killed by roadside bombs and the seventh was killed by small arms fire. The military said only that the two Marines were killed in combat operations in Anbar province.

In the town of Mandali, on the Iranian border 60 miles east of Baghdad, a suicide bomber walked into a packed market cafe and blew himself up Wednesday, killing 15 people and wounding 20 others, police said.

The cafe in the mixed Sunni, Shiite and Kurdish city, was usually frequented by police, but no police officers were there at the time, police said. Police said a man of in his 30s wearing a heavy jacket despite the searing heat was seen walking into the cafe just seconds before the blast.

In another devastating attack, a suicide bomber blew himself up in the house of two brothers who were supporting a Sunni alliance opposed to al Qaida in the Anbar province, killing 10 people, including the men, their wives and their children, police Lt. Col. Jabar Rasheed Nayef, said Wednesday.

The attacker, a 17-year-old neighbor, broke into the house of the two men, Sheik Mohammed Ali and police Lt. Col. Abed Ali, and detonated his bomb belt about 11 p.m. Tuesday in Albo Obaid, about 60 miles west of Baghdad.

The targeted men were part of the Anbar Salvation Council, a group of local Sunni tribal leaders who had banded together with government support to fight al Qaida, Nayef said.

More than 4,000 U.S. soldiers, backed by Iraqi forces have been searching for more than a week and a half for the missing Americans. U.S. and Iraqi troops endured temperatures of 115 degrees Tuesday as they trudged through canals waist-deep in sewage, searching for the missing soldiers.

A senior Iraqi army officer in the Babil area told The Associated Press that the body found today was that of an American soldier. The officer spoke on condition of anonymity because he is not authorized to speak to the media.

But the U.S. military said no determination had been made.

“Iraqi police did find the body of a man whom they believe may be one of our missing soldiers,” Maj. Gen. William C. Caldwell told reporters. “We have received the body and we will work diligently to determine if he is in fact one of our missing soldiers.”

He said that if the body proves to be one of the missing soldiers, his family will be notified first.

In an interview with the Army Times newspaper last week, Gen. David Petraeus, the top U.S. commander in Iraq, said he believed at least two of the missing soldiers were alive.

“As of this morning, we thought there were at least two that were probably still alive,” he said in the interview, which was posted Saturday on the newspaper's Web site.

“At one point in time there was a sense that one of them might have died, but again we just don't know.”

Also Wednesday, a parked car bomb exploded in a parking lot south of Baghdad, killing three civilians and wounding 15 others, police said. The attack took place in the town of Jbala, about 45 miles south of Baghdad.

In other violence, gunmen drove into a commercial area in central Baghdad and opened fire on shops, killing four civilians and injuring 14 others, police said. The attack broke out in the Khulani neighborhood near a historic Shiite mosque. A joint patrol of U.S. troops and Iraqi security officers drove off the attackers, police said.

A day earlier, a car bomb exploded at an outdoor market in a Shiite area of Baghdad, killing 25 people and wounding at least 60. At least 100 Iraqis were killed or found dead nationwide Tuesday, according to police. They included 33 people found shot execution-style - presumably by sectarian death squads - and their bodies scattered across Baghdad.