Elsewhere, three American civilian contractors were wounded in an explosion in the northern oil center Kirkuk. First reports said the blast was from a mortar, but Lt. Col. Matt Croke said officials later concluded it was a bomb.
The killings occurred after U.S. helicopter gunships struck targets in central Iraq on Sunday, according to other witnesses.
The bodies of the two male soldiers could be seen lying in the street next to their vehicle in Mosul's Ras al-Jadda district with their throats cut. The U.S. command in Baghdad said it had no information on the incident.
A 4th Infantry Division soldier was killed Sunday and two others were wounded when a roadside bomb exploded in Baqouba, 35 miles northeast of Baghdad, the military said.
Two soldiers from the 1st Armored Division were killed and another was injured when an M-1 Abrams tank crashed into their Humvee west of the capital, the military said Sunday. In another accident, near Balad, a soldier drowned when his vehicle fell into a canal.
In other developments:
U.S. officials have warned of more attacks against coalition forces as the Islamic holy month of Ramadan nears its end Tuesday.
The blast in Kirkuk, 150 miles north of Baghdad, occurred overnight on the compound of the National Oil Company. Three American employees of the U.S. firm Kellogg Brown & Root suffered facial cuts from flying glass, Croke said. On Friday, insurgents rocketed the Palestine Hotel in Baghdad, where many KBR employees as well as international journalists and others stay. One civilian was wounded.
"We all know that Americans are being threatened," Croke said.
In Samara, about 75 miles north of Baghdad, Iraqi police said six U.S. Apache helicopter gunships blasted marshland after four rocket-propelled grenades were fired at the American military garrison at the northern entrance to the city. One Iraqi passer-by was killed in the air attack.
Also Sunday, a spokeswoman with Iraq's Governing Council said the body has chosen an Iraqi-American woman and veteran lobbyist as its ambassador to the United States.
Foreign Minister Hoshyar Zebari announced Francke's appointment at a news conference Sunday. Francke led the Iraq Foundation, a Washington-based pro-democracy group, and has helped in post-Saddam Hussein government planning.
She was born in Baghdad but has not lived here full-time in more than 30 years. She became a U.S. citizen in 1987.
"I will sincerely express the ambitions of the Iraqi people and ... take care of the Iraqi community in the United States, which amounts to some 400,000 people," Francke told reporters. "The Iraqi Embassy used to be a source of fear for this community, rather than being a place to render services."
The appointment will renew diplomatic ties between Washington and Baghdad 13 years after they were severed in 1990 when Saddam Hussein invaded Kuwait.
Discussions about appointing an envoy came after an agreement between the Bush administration and the Governing Council to hand over power to a new, transitional Iraqi government by the end of June.
The council also will soon appoint a replacement for a member assassinated two months ago, council member Mahmoud Othman said. Aquila al-Hashimi, a Shiite Muslim member of the 25-seat group, was mortally wounded Sept. 20, the highest Iraqi official killed by suspected Saddam loyalists.
Her replacement is expected to be a Shiite Muslim since the Council, installed on July 13, has been divided proportionally between Iraq's different sects and ethnic groups: 13 Shiite Arabs, five Kurds, five Sunni Arabs, one Christian and one ethnic Turk.
On Saturday, insurgents hit a civilian cargo plane with a surface-to-air missile, but the aircraft landed safely. The plane was the first civilian airliner to be hit by insurgents, who have shot down several military helicopters with shoulder-fired rockets. DHL and Royal Jordanian, the only commercial carrier flying into Baghdad, immediately suspended flights.
Suicide bombers struck two police stations northeast of Baghdad within 30 minutes on Saturday. In the market town of Khan Bani Saad, a Chevrolet Caprice sped through a guard's gunfire Saturday morning and exploded at the station gate, police said.
The U.S. military said 10 people were killed in one and four in the other.
Elsewhere, an Iraqi police colonel in charge of protecting oil installations was assassinated in northern Iraq, part of what appeared to be an insurgent campaign against U.S.-backed security forces.
Col. Abdul-Salam Qanbar, who was in charge of a police force in the northern city of Mosul, was fatally shot Saturday evening while heading to a mosque, a spokesman said.
"It is clear that the terrorists have targeted Iraqis, the very Iraqis who are trying to improve the security in Iraq and the lives of ordinary Iraqis," coalition spokesman Charles Heatly said.