Updated

Gunmen killed two American soldiers and wounded another nine early Tuesday in the town of Fallujah, an area of strong support for Saddam Hussein's fallen Baath party.

U.S. troops returned fire, killing two attackers and capturing six Iraqis for questioning.

In the past three days, seven American soldiers have died in attacks or accidents in Iraq.

A U.S. soldier died Tuesday and two others were injured in a road accident near the town of Tallil when their tractor-trailer collided with another vehicle. Another soldier drowned after diving into an aqueduct in northern Iraq, U.S. Central Command said.

Yet the American general commanding troops in Baghdad say security is improving in Iraq and that U.S. authorities are making inroads toward improving life for ordinary Iraqis.

In other news, a possible brother-in-law of Saddam was arrested in northern Iraq, according to the U.S. military.

But a newspaper report says the man is Saddam's son-in-law. Regardless of the relationship, Mulhana Hamood Abdul Jabar is not on the U.S. list of the 55 most-wanted Iraqis. He was detained early Sunday and taken to Baghdad International Airport for questioning.

The military says Abdul Jabar was arrested after he drove two wounded men to a hospital. The two injured men, who were suffering from gunshot wounds, will be questioned when they recover.

The attack in Fallujah happened around midnight at a checkpoint in the town about 30 miles west of Baghdad.

Initial reports said the Americans were fired upon from many directions, including from a mosque, U.S. officials said. But townspeople said only two men fired shots and that the U.S. troops quickly killed them.

"Who knows what they were thinking when they engaged U.S. soldiers," said Maj. Randy Martin, a spokesman for the U.S. Army's V Corps. "I know we suffered casualties, and the enemy paid a price."

The U.S. soldiers killed or wounded were from the 3rd Armored Cavalry Regiment, based in Fort Carson, Colo. Their names were not released.

The attackers used rocket-propelled grenades and small arms in the attack, according to a statement from U.S. Central Command, but Martin said the grenade was thrown by hand.

Area resident Bashir Jasim said the two Iraqis stopped their pickup truck at a traffic checkpoint, stepped out and opened fire. They were killed immediately by the Americans, he said. Other townspeople relayed similar stories.

But Martin said two vehicles approached the checkpoint together, and that men from the second opened fire and threw the grenade after U.S. troops found weapons in the first vehicle.

U.S. troops responded with fire from Bradley Fighting Vehicles, machine guns and small arms.

The attack came as Maj. Gen. Buford Blount III, the U.S. general in charge of troops in Baghdad, said that violence against U.S. forces appeared to be random incidents by irregulars loyal to Saddam and that overall security in Iraq's capital is improving.

Blount said most looting has ended and that joint U.S.-Iraqi police patrols have been arresting 40-50 people daily for more serious crimes.

"Every week we've had some kind of attack, whether it be a drive-by shooting or a (rocket-propelled grenade)," he said. "Yesterday it was a land mine. But it's very small groups, one or two people, in isolated attacks against our soldiers."

Blount said progress was also being made in normalizing electricity and water supplies to all of Baghdad, but that many of the difficulties in restoring utilities predate the war.

Fallujah is no stranger to conflict since U.S. forces entered the city.

Protests against the Army's presence in the town -- which was favored under Saddam's rule -- turned violent when U.S. soldiers fired on protesting crowds on April 28 and April 30, killing 18 Iraqis and wounding at least 78.

On Tuesday, Fallujah residents said they were growing increasingly angry with the American presence.

"Every Iraqi is ready to sacrifice his life for resistance," said Safa al-Jubair, a 27-year-old street vendor. "We are 26 million Iraqis and we are all resisting and, God willing, occupation will end."

U.S. forces have run into trouble before in Fallujah, whose 200,000 people benefited greatly from Saddam's Baath regime. Saddam built chemical and other factories that employed Fallujah's young men and gave others places in his elite Republican Guard.

U.S. forces around Iraq have become even more threatened recently.

A soldier was killed Monday and another wounded when their convoy was ambushed near Hadithah in northern Iraq. Later Monday, Central Command said a U.S. soldier was killed and three injured when a Humvee ran over a land mine or unexploded ordnance in an apparently hostile act.

Witnesses in the wealthy Baghdad neighborhood of Yarmouk said they heard several explosions and a 15-minute burst of gunfire along the road to the airport.

On Sunday, a U.S. soldier was killed and another injured in southern Iraq when a munitions dump exploded. The blast was not thought to be a result of hostile action, Central Command said.

In Baqubah, 45 miles northeast of Baghdad, U.S. soldiers shot and killed a woman who tried to approach them carrying two hand grenades after other people threw explosives at U.S. soldiers, Central Command said.

Iraq's civilian administrator Paul Bremer said Monday that troops have done a great deal to re-establish stability, including turning on water and electricity and improving basic services, and will start a program to help the nation rebuild its economy.

But he acknowledged: "There is still a lot to do, there's no doubt."

The International Atomic Energy Agency said nuclear inspectors would return to Iraq by the end of the week to ensure nuclear material stored at the Tuwaitha complex southeast of the capital remains safe and accounted for.

The mission will be limited to inspecting whether Iraq is fulfilling its obligations under the Nuclear Nonproliferation Treaty and is not related to weapons inspections, IAEA spokesman Mark Gwozdecky said in Vienna, Austria.

Another team of international experts arrived in Iraq to inspect mobile labs that the United States believes were part of a suspected biological weapons program, said U.S. Col. Tim Madere.

The Associated Press contributed to this report.