U.S. ground forces fought insurgents on the outskirts of Fallujah early Monday, and U.S. warplanes pounded the insurgent-held city, as a full military assault appeared increasingly imminent. On Sunday, Iraq's interim government had announced a state of emergency for most of the country.

Overnight, Iraqi forces backed by U.S. troops seized Fallujah's main hospital, located across the Euphrates River from the bulk of the city -- connected by the ironwork bridge from which the burned bodies of U.S. security contractors were hanged last spring. The largely symbolic action put an Iraqi imprimatur on an offensive that will necessarily be led by American armor, aircraft and troops, which Monday morning were still awaiting orders to advance. U.S. commanders have not said when the major offensive would start.

The state of emergency was issued by the interim prime minister, Ayad Allawi. The order, which imposes martial law, heightened a sense of crisis in Iraq and fueled fears that an offensive in Fallujah would unleash a wave of counterattacks, which insurgents appeared to have already begun elsewhere in the country. Violence in six cities in the past two days has killed more than 80 people.

"This will send a very powerful message that we are serious," Allawi said after meeting with cabinet ministers who approved the emergency measure for all areas of the country except the relatively peaceful Kurdish northeast. The order will run for 60 days but could be extended through elections planned for January.

"We want to secure the country so elections can be done in a peaceful way and the Iraqi people can participate in the elections freely, without the intimidation by terrorists and by forces who are trying to wreck the political process in Iraq," Allawi said. "So this is a message. I hope the terrorists get it because we are not going to be easy on them."

It was not immediately clear which emergency powers Allawi intended to invoke or how they would help his government assert control of the country, which he described as largely calm during a visit to Washington six weeks ago.

Technically, the state of emergency gives the government wide powers to impose curfews, restrict movement and suspend liberties. But Iraq's security services have struggled to stand up to insurgents who operate with better weapons and intelligence, especially in the Sunni Muslim midsection of the country where resistance has proved most stubborn. U.S. and allied foreign military forces routinely operate on their own, making arrests, engaging in firefights and patrolling independent of civil authorities.

Insurgents on Sunday again targeted police stations and other symbols of the interim government. Twenty-two police officers were killed in Haditha and Haqlaniya, two towns northwest of Fallujah, and the attackers included foreign Arabs, according to news reports. Many of the officers were lined up and shot, according to the reports.

Those assaults followed a flurry of car bombings and mortar attacks Saturday that killed more than 30 people in Samarra, a Sunni Muslim city about 65 miles north of Baghdad. U.S. and Iraqi forces had reclaimed the city from insurgents last month in an operation that has been cast as a model for the attack on Fallujah.

Twenty-one Iraqi National Guard recruits were killed over the weekend as they were returning to their homes in Najaf after traveling to the capital to join up. The Najaf police chief, Ghalib Jazaari, said gunmen, tipped off by informers in the recruiting office, killed 13 of the recruits Saturday and eight more Sunday as they passed through the town of Latifiyah, a hotbed of insurgents about 70 miles north of Najaf. "We have the bodies of the first 13 here," Jazaari said.

In other attacks Sunday, a car bomb exploded in Baghdad outside the home of the interim finance minister, Adil Abdul-Mahdi, killing two people. Mahdi was not home during the attack, the Associated Press reported. And two U.S. soldiers were killed and five were wounded in attacks in and around Baghdad, news services reported.

In addition, two provincial officials were assassinated south of Baghdad as they traveled to the funeral of another official. An Iraqi policeman was shot dead while driving to his home in Baghdad, the military said, and his police car was stolen.

A British contractor was killed in the southern city of Basra, according to Britain's Defense Ministry.

The wave of attacks came as insurgents vowed to take the battle across Iraq if 10,000 U.S. and Iraqi troops proceed with a threatened offensive against Fallujah, a city that has become a symbol of resistance since it fell under insurgent control in April.

The assault appeared imminent. U.S. forces cited Allawi's emergency decree in announcing that they had sealed off the city late Sunday, declaring in a statement that troops were "finishing final preparations for an assault on Fallujah."

Senior Marine commanders gathered troops for hollered pep talks, invoking the 1968 assault on the Vietnamese city of Hue, a battle that looms large in the lore of the Corps.

"The window is closing, absolutely," Allawi said, adding that Fallujah residents "have been taken hostage by a bunch of terrorists and bandits and insurgents who were part of the old regime. They had been involved in atrocities when Saddam [Hussein] was around. Our government is determined to safeguard the Iraqi people."

Allawi's warning was immediately answered by a Sunni group that has been a leading voice for the resistance.

"This will increase the violence," said Mohammed Bashar Faidhi, spokesman for the Association of Muslim Scholars, which represents 3,000 Sunni Muslim clergy in Iraq. "The government is like a man walking in the dark who wants to avoid a small hole and falls into a big hole."

"At this point, the government can't even protect itself," Faidhi said. "How can it impose a state of emergency? Allawi, when he travels, half of the American Army accompanies him!"

Faidhi said the clerics' association supported a proposal aimed at reducing support for armed struggle by addressing Sunni concerns about U.S. influence on the election process and restricting the movements of U.S. forces. But Faidhi said the group's skepticism was being realized as preparations for the assault on Fallujah advanced.

"After breaking into Samarra, new people joined the resistance in order to get revenge," he said. And if Fallujah is attacked, "I don't exaggerate when I say the resistance will double."

In Haditha, about 30 insurgents mounted a three-hour coordinated assault on the city's police headquarters starting at 9 p.m. Saturday.

"First of all, we were attacked by mortars," Lt. Muneef Abdullah said. "Then the armed men came and started shooting and throwing hand grenades. When we tried to defend ourselves, they started launching" rocket-propelled grenades.

"We called the Americans to come and help us," he said, "but unfortunately they took three hours, as if they were coming to a wedding."

Other accounts of the attacks on the police stations in Haditha and Haqlaniya, in western Anbar province, which includes Fallujah, said that some of the Iraqi police officers were killed execution-style. The Reuters news agency said the attackers took the captured policemen to an oil-pumping station and shot them to death.

Last month, insurgents massacred 49 unarmed Iraqi army recruits after capturing them on a road northeast of Baghdad. A group led by Abu Musab Zarqawi, a Jordanian linked to al Qaeda, asserted responsibility for those killings.

Special correspondent Saad Sarhan in Najaf contributed to this report.

U.S. Marines prepare for action against Fallujah during a weekend in which more than 80 people, most of them Iraqi security officers or recruits, were killed in attacks.