BAGHDAD, Iraq — A roadside bomb killed seven U.S. soldiers in northwest Baghdad and two Marines were killed in western Iraq yesterday, the deadliest day for American forces since six members of a Fort Lewis-based Stryker brigade died with eight other soldiers in a suicide attack on a U.S. base.

The bombing came as Interim Prime Minister Ayad Allawi warned yesterday that insurgents were likely to further intensify their assaults with the approach of elections scheduled for Jan. 30, and he extended a 2-month-old state of emergency for 30 days.

A new Pentagon assessment said Iraqi election officials have been unable to operate — either freely or at all — in parts of the country where a third of the population lives, including regions that are home to most of Iraq's Sunni Arab minority, Knight Ridder Newspapers reported.

The commander of U.S. ground forces in Iraq, Lt. Gen. Thomas Metz, said security was poor in four of Iraq's 18 provinces but that postponing the election posed greater dangers. "I think there is a greater chance of civil war with a delay than without one," Metz said in Baghdad.

Brent Scowcroft, a retired Air Force lieutenant general and the national security adviser under the former President Bush, yesterday warned that "the election, instead of turning out to be potentially a promising transformation of the conflict, has great potential for deepening the conflict. Indeed, we may be seeing an incipient civil war."

Scowcroft, who spoke at a luncheon sponsored by the New America Foundation, a centrist, nonpartisan Washington think tank, has long been a critic of the Iraq war, but his stark warning about potential civil war marked one of the most ominous assessments about the implications of the upcoming election from a high-ranking former official.

A statement issued by the military said soldiers with Task Force Baghdad were on patrol when their Bradley Fighting Vehicle hit an explosive device. All seven of the vehicle's occupants were killed in the blast. Newsday reported that the dead were with the 69th Infantry Regiment, a National Guard outfit from New York state.

Earlier yesterday, two members of the 1st Marine Expeditionary Force were killed in fighting in volatile Anbar province. No other information regarding their deaths was released.

Meanwhile, police in northern Iraq said they had found the bodies of 18 Iraqis who had been abducted on Dec. 8 while traveling from Baghdad to work at a U.S. base west of Mosul. The police identified the victims as Shiite Muslims, all males between the ages of 14 and 20, and said each had his hands tied behind his back and had been shot in the head.

Across Iraq this week, insurgents have killed more than 90 people in attacks on Iraqi and U.S. forces and members of Iraq's interim government.

On Tuesday, five American troops were killed, including three Task Force Baghdad soldiers who died in a roadside bombing, one who was slain in Anbar, and another who died in Balad, north of Baghdad.

Yesterday's toll was the highest for the U.S. military in Iraq since a suicide bombing at a mess tent in Mosul on Dec. 21 killed 22 people, including 14 U.S. soldiers and three American contractors.

The latest deaths brought the number of U.S. troops killed since the beginning of the Iraq war in March 2003 to 1,350, according to an Associated Press count. At least 1,063 died as a result of hostile action.

Allawi called the decision on prolonging the state of emergency a precaution. He blamed former members of Saddam Hussein's regime for the continuing violence.

"Saddam's followers, who have intensely shed the blood of our people and army, are still in action clandestinely, allying with a bunch of criminals, murderers and terrorists who are the enemies of our people and our progress," Allawi said during a ceremony to mark the national Army Day holiday.

"Our army and police have become targets of these hateful forces that fear the formation of the people's army and police."

Allawi, a secular Shiite, is insisting the elections go forward, despite calls from some Sunni religious leaders for a boycott. Sunni Arab political parties have largely withdrawn from the race because of security fears, particularly in western Iraq. Some have sought a delay of the vote.

The election is for a 275-member National Assembly, which will appoint a central government and draft a permanent constitution.

Parties and coalitions of parties have submitted lists of candidates for the nationwide election. Each voter will have a single vote to cast for a list, and parties will receive a number of seats in the National Assembly proportionate to their percentage of the vote.

Allawi, who was appointed by the United States when it handed sovereignty to Iraq in June, is running a slate of candidates for the national assembly. He has been trying to appeal to voters by promising a strong hand against the insurgents.

The emergency powers that Allawi extended give police expanded arrest powers and set nighttime curfews.

The state of emergency, announced two months ago, was extended for 30 days throughout the country except for the northern Kurdish-run areas, a government statement said. The decree includes a nighttime curfew and gives the government additional power to make arrests and launch military or police operations.

The election is expected to shift power to the Shiite Muslim community, an estimated 60 percent of the population that had been dominated by the Sunni Arab minority since modern Iraq was created after World War I.

The Bush administration hopes the voting will help end the insurgency in Iraq by creating a government with broader popular support. Instead, Scowcroft said he believed there was "a distinct possibility" that the election could lead to the break-up of the country by prompting violence between Shiite and Sunni forces that convinces the Kurds to secede.

At the luncheon, attended by journalists and foreign policy experts, Scowcroft said the risk was that the election would deepen feelings of estrangement among Sunni Muslims, who constitute only an estimated 20 percent of the population but dominated Iraq under Saddam Hussein. Kurds represent the other significant political group.

Scowcroft said he believed the insurgency in Iraq "is gradually morphing" from a resistance by elements of the former regime into a broader "Sunni revolt" driven by fear that the Shiite Muslim majority will elect a government controlled by its own members.

The leading Sunni political party, the Iraqi Islamic Party, has called for the election to be delayed until security improves in Sunni regions of the country. Interim President Ghazi Ajil Yawer, a Sunni Muslim, also suggested this week the election might need to be delayed.

Scowcroft's comments were reported by The Washington Post.