A team of U.N. nuclear weapons inspectors went on a road trip Tuesday morning, driving west from Baghdad across 250 miles of desert to a uranium mine near the Syrian border.

Four other groups were inspecting sites closer to the Iraqi capital, including, for the third time in a week, the country's largest nuclear facility. More monitors flew in later in the day.

The inspectors have been working in a "calm and professional" manner, Iraq's chief liaison to the U.N. teams told a Baghdad newspaper. But he again complained about last week's surprise inspection of one of Saddam Hussein's palaces, calling it an American-inspired provocation.

Also Tuesday, Iraqi Vice President Taha Yassin Ramadan rejected U.S. skepticism of Baghdad's report to the U. N. Security Council on its weapons program and said an attack on his country would be a challenge to the whole region.

"Any aggression against Iraq is the start of more aggression on the neighborhood," he said in an interview with Al-Jazeera, the Arab satellite television network, which showed only a brief segment of the exchange.

In Washington, Pentagon officials said allied aircraft bombed an Iraqi surface-to-air missile system Tuesday after it was moved into a restricted zone earlier in the day.

The attack took place in Al Amarah, about 165 miles southeast of Baghdad. It was unclear if Iraqi forces fired at U.S. and British warplanes patrolling the southern no-fly zone. U.S. officials say the mere presence of air-defense systems inside such zones represents a threat to coalition pilots.

Tuesday marked two weeks since the inspections resumed after a four-year hiatus. The Security Council resolution currently in force requires Baghdad to give up any remaining chemical or biological weapons, and shut down any programs to make them. Iraq denies it still has such weapons or programs.

The Iraq field missions were expanding as U.N. and American analysts began combing through 12,000 pages of documents submitted by Iraq to the United Nations over the weekend, detailing past programs of weapons of mass destruction and what it says are purely civilian programs today in the chemical, biological and nuclear areas.

Inspections in the 1990s, after Iraq's defeat in the Gulf War, led to the destruction of tons of chemical and biological weapons, and to the dismantling of Iraq's program to try to build atomic bombs.

The mining operations at Akashat, to which the first team headed on Tuesday, were scrutinized by U.N. nuclear inspectors in the 1990s.

In the 1980s, the phosphate deposits at Akashat had been exploited for their uranium content as well as for fertilizer, producing some 100 tons of uranium over six years.

The U.N. team reported heading there on Tuesday for an unannounced inspection presumably wanted to "re-baseline" their information, assessing current Akashat operations.

The enormous complex surrounded by antenna posts, some broken, sat in an otherwise empty quarter of the desert. Reporters were unable to follow the inspectors inside.

Other nuclear inspectors headed again for al-Tuwaitha, Iraq's major nuclear research center, 15 miles southeast of Baghdad, Iraqi Information Ministry officials reported.

It was their third recent visit to the sprawling complex, where Iraqi scientists in the 1980s worked on developing technology for enriching uranium to levels usable in bombs.

A third U.N. team was reported to have gone to a veterinary medicine establishment at Abu Ghraib, just west of Baghdad — presumably the Amariyah Serum and Vaccine Institute, site of biological weapons-related research in the 1980s.

That institute is reported to have expanded its storage capacity, to an extent the U.S. government says exceeds Iraq's needs. Iraq contends the facility only makes and stores human vaccines.

Other inspectors were reported to have gone Tuesday to a military training center in Baghdad and to an industrial facility at al-Furat, just south of the Iraqi capital. The purposes of those visits were not immediately known.

In London, Prime Minister Tony Blair said it would be "naive" to believe Saddam plans to comply with U.N. demands for his disarmament in the field of weapons of mass destruction.

In an interview with the Financial Times, Blair also restated the readiness of the United States and Britain to take military action against Saddam.

"If there is a breach and Saddam doesn't comply, then we are prepared to take action," Blair was quoted as saying.

Later Tuesday, more inspectors — about 25 were expected — arrived on a flight from a U.N. rear base on the Mediterranean island of Cyprus, bolstering the U.N. inspection staff to about 70. Inspection team leaders have said they hope to expand operations to eight teams by year's end.

In an interview published Tuesday in the weekly al-Rafidayn, Lt. Gen. Hossam Mohammed Amin, chief Iraqi liaison, said of the inspectors' "behavior" that "we're satisfied with it so far because it is calm and professional."

Iraqi officials have complained, however, about the U.N. inspection Dec. 3 of Baghdad's al-Sajoud palace, one of Saddam's many presidential palaces. Amin reiterated that criticism.

"The visit took place under pressure from the United States of America to create a crisis or confrontation between Iraq and inspection teams, but this did not happen," he asserted.

Iraq's still-simmering resentment of the palace inspection has led to some speculation in the West that Saddam Hussein may have been on the grounds of al-Sajoud when the inspectors suddenly arrived. The U.N. teams did not see the Iraqi president, but did run into his private secretary.

Inspections of such "presidential" sites contributed to the U.N.-Iraqi tensions that ended with the collapse of the previous inspection regime in 1998. The new U.N. resolution declares the monitors have unrestricted power to inspect such sites.

Asked how long he expects the new U.N. inspections to take, Amin said that if the inspection agencies are "sincere," he thinks they should take eight months.

"Then the Security Council should suspend the sanctions imposed on Iraq and the monitoring process would continue," he said.

He was referring to international economic sanctions imposed on Iraq after it invaded Kuwait in 1990, and to U.N. plans to establish a long-term system of monitoring Iraq's military-industrial complex — via surveillance gear, required reports and periodic visits.

The Associated Press contributed to this report.