BAGHDAD, Iraq -- With U.S. troops heavily armed and bunkered behind concrete and razor wire, guerrillas are pointing their guns at softer targets like Iraqi police and civilians, top U.S. military and civilian officials said Tuesday.
American officials expect attacks on Iraqis working with the coalition to surge as the U.S.-led administration begins handing power to local leaders.
After dark, three large explosions shook the center of Baghdad from the city's western half. The blasts triggered a warning siren in the "Green Zone" housing the U.S. headquarters.
A coalition spokeswoman said the blasts occurred outside of the zone at a police station, a bus station and a third, unknown location. She had no information on casualties. The area is less than a half-mile from the "Green Zone."
"The security situation has changed," said top U.S. administrator L. Paul Bremer at a news conference with Gen. John Abizaid, the chief of the U.S. Central Command whose area of responsibility includes Iraq.
Bremer said coalition troops would do their best to protect upcoming leadership debates and caucuses.
"We have to anticipate that there will be a level of terrorism in the months ahead," he said. "As the process of democracy moves forward over the next several months, they may try to attack the institutions of democracy."
Abizaid said the number of daily attacks on coalition forces dropped by about half over the past two weeks.
But another U.S. military official, Col. William Darley, said attacks peaked at more than 40 per day about two weeks ago and have since dropped to about 30 per day -- about the same as in October and well over the number in August and September.
More than five dozen U.S. troops were killed by hostile fire in November, more than any other month since the end of major combat in Iraq on May 1.
Since operations began in Iraq, 297 U.S. service members have died of hostile action, including 183 since May 1 when President Bush declared an end to major fighting.
Hotspots Fallujah and Ramadi, two Sunni-dominated cities west of Baghdad, have seen fewer attacks recently, but unrest has persisted in the capital and spread north to Mosul and Kirkuk.
The guerrillas, whom Abizaid described as regional cells of ex-Baath Party loyalists, have launched devastating strikes on the Iraqi police. The intent, the officials said, is to intimidate Iraqis.
"If they can't reach the coalition, they go after the people they can touch," Darley said.
Those attacks include two car bombs at police stations last weekend, the assassination Saturday of a police colonel and the killing Sunday of a police chief.
The shift in guerrilla targets follows a decision by the U.S. command to aggressively pursue insurgents before they can strike.
Speaking in Washington on Tuesday, Defense Secretary Donald H. Rumsfeld cited a long list of statistics on the results of recent U.S. efforts to defeat the insurgency -- including a rare reference to numbers of opposition fighters killed.
He said that last week alone, U.S.-led forces conducted nearly 12,000 patrols and more than 230 raids.
"They captured some 1,200 enemy forces, and killed 40 to 50 enemy fighters and wounded some 25 to 30," Rumsfeld said. "That's a one-week snapshot, but it provides a sense of the determined offensive pressure which the coalition is applying against the enemy."
In Iraq, the 4th Infantry Division said its soldiers arrested 18 Iraqis during nearly 200 raids over the past 24 hours in its sector north of Baghdad.
Troops from the 3rd Armored Cavalry Regiment were encircling three towns along the Syrian border in a search for weapons and fighters, according to a U.S. News and World Report correspondent who returned from the area Tuesday.
The troops established a cordon Thursday around the towns of Husaybah, Karabilah and Sadah, total population 120,000, and haven't let anyone in or out, the reporter said, adding that troops were conducting sweeps through the encircled territory.
The reporter, Bay Fang, said soldiers have detained more than 300 people and discovered several weapons caches, including one that held about 800 World War II-era torpedoes.
In Tikrit, the 4th Infantry Division said U.S. gunners responded with artillery Tuesday when insurgents fired mortars at a forward operating base. A quick response team pursued the attackers and captured 25 people, including one who had been wounded. One Iraqi was killed, the division said.
The division said it was "investigating reports that civilians may have been injured during the course of the artillery counter-fire against the enemy mortar position."
Also Tuesday, the aid agency CARE Australia said it had pulled its six international staffers out of Iraq and told its 70 Iraqi employees to stay home after a weekend rocket attack on its Baghdad office.
Australian Broadcasting Corp. radio said CARE Australia received a specific threat from a group calling itself the Iraqi Resistance.
"We are going to kill you and attack your places without any further notice," the warning reportedly said. "We are issuing this communique after we attacked the CARE office and we are letting you know that the deadline for all such places, hotels, houses, oil companies, will be the third and the last day of Eid (al-Fitr). Otherwise these buildings will be totally destroyed."
Eid al-Fitr marks the end of the holy month of Ramadan. In Iraq, the end of Ramadan varies, with some Muslim groups marking it Monday, others Tuesday and still others Wednesday.
The Red Cross, the United Nations and other humanitarian groups have withdrawn international staff and sharply curtailed operations due to the security situation in Iraq.
Abizaid described the insurgency as a principally homegrown campaign involving "agents of the former regime" of ousted leader Saddam Hussein aided by a few foreigners.
"Foreign fighters are coming in and it is not correct to say that there are floods of foreign fighters coming in or thousands. The number is small," he said.
Abizaid concurred with statements from regional U.S. military commanders that Iranians weren't thought to be among the insurgents.
"I wouldn't characterize any Iranian I know of as a foreign fighter," the general said.
After the briefing, Darley characterized the 70 or so Iranians among some 300 foreigners in U.S. custody in Iraq as "spies" or "suspected anti-coalition people."