BAGHDAD, Iraq - U.S. soldiers arrested more than 400 people in northern and central Iraq, part of a campaign against insurgents who added a new tactic Tuesday: targeting Iraqi civilians deemed too close to America.

The insurgents' hit-and-run campaign continued despite the tough U.S. crackdown, with an Army soldier shot and killed late Monday while on patrol in Baghdad.

The U.S. military said raids that began Sunday on Iraqi homes and businesses in Baghdad and northern Iraq were meant to "isolate and defeat remaining pockets of resistance."

The operation is stirring deep resentment, with Iraqis rounded up, handcuffed and interrogated even, say townspeople, when they did nothing wrong.

Late Monday, U.S. forces raided an outdoor cafe in Baghdad's Azamiyah neighborhood where two dozen men were playing backgammon and drinking tea. All were lined up against a fence, blindfolded, forced to kneel and carted away on trucks. They were released later, after none turned out to be a suspect.

U.S. soldiers said they had no choice other than to cast a wide net in hopes of catching attackers who intelligence reports said spent time at the cafe.

The insurgents took their fight to a new level Tuesday, firing shots into the mayor's office and courthouse in Fallujah and a police station in Khaldiyah - offices that have been cooperating with the U.S.-led occupation. No injuries were reported.

The shootings were the first known attacks directed against Iraqi officials for cooperating with U.S. forces and represented a new front in the insurgents' attempt to undermine U.S. forces in Iraq.

Some officials think remnants of Saddam Hussein's security apparatus have begun to establish guerrilla cells, though it remained unclear whether the attacks Tuesday were centrally organized.

Over three days, troops in Baghdad and northern Iraq carried out 69 raids and arrested 412 people, a U.S. military statement said.

In the Baghdad area, troops seized 121 rifles, two submachine guns, 19 pistols, 18 rocket-propelled grenades, four machine guns, 31 pounds of explosives and chemical protective masks, the statement said.

Two Sunni tribal leaders in Ramadi, about 60 miles west of Baghdad, sharply criticized the U.S. actions.

"For every action they should expect a reaction," said Sheik Saad Nayef al-Hardan, the chief of Iraq's largest Arab tribe, the Dulaim. "Those attacks are a sign that the tolerance to the humiliation is running out."

Another senior tribal leader in Ramadi, Abu Adel, said the guerrilla attacks on U.S. forces were acts of self-defense committed by an "underground operation."

"We are a proud people, and we will not accept this humiliation," he said. The Americans "should beware the wrath of the Iraqi people."

On Monday night, a sniper shot and killed a U.S. Army soldier riding in a Humvee with the 1st Armored Division's 1st Brigade. The soldier's name was not made public.

L. Paul Bremer, the top U.S. official in Iraq, announced the establishment of a judicial review committee and criminal court, saying they will be used to crack down on criminals and purge Iraq's judiciary of Baath Party loyalists.

The reforms aim to upgrade a judicial system that catered to a dictator's whims more than the rule of law.

Some judges and lawyers scoffed at what they called U.S. interference in their courts.

"The Americans are an occupation force, and we are the source of one of the oldest codes of law - Hammurabi's Code," judge Qassem Ayyash said. "It's like teaching a driver how to drive."