A team of U.N. arms inspectors arrived in Iraq on Monday to relaunch a search for weapons of mass destruction on a mission that could trigger a U.S.-led war. Chief weapons inspector Hans Blix and Mohamed ElBaradei, director of the International Atomic Energy Agency, flew into Baghdad from Cyprus with a team of about 30, the first U.N arms inspectors to visit Iraq for four years.

"Let me tell you that we have come here for one single reason and that is because the world wants to have assurances that there are no weapons of mass destruction in Iraq," Blix told reporters on arrival.

"The situation is tense at the moment but there is a new opportunity and we are here to provide inspection which is credible...We hope we can all take that opportunity together."

The members of Blix's United Nations Monitoring Verification and Inspection Commission (UNMOVIC) arrived aboard a privately chartered C-130 aircraft carrying the U.N. insignia.

Blix was greeted by Husam Mohammed Amin, head of the Iraqi National Monitoring Directorate, the office liaising with U.N. arms inspectors.

The U.N. team was expected to go straight to the U.N. inspectors' old offices at the Canal Hotel in Baghdad before starting initial work on logistics like hiring vehicles and setting up laboratories.

Formal inspections were not due to start until November 27.

"We should have about 80 to 100 inspectors there by Christmas (December 25). We'll gradually build it up and they'll be rotated in and out," an UNMOVIC spokesman said in Cyprus.

The inspectors arrived a day after U.S. Defense Secretary Donald Rumsfeld said Iraq tried to shoot down U.S. and British warplanes in what he said was a violation of the November 8 U.N. resolution that paved the way for the inspectors' return.

But Rumsfeld stopped short of suggesting the United States would carry the issue immediately to the U.N. Security Council.

"The resolution addresses the subject and it's up to the Security Council and member states to make the conclusion on what is, or is not, in material breach. My impression is that they will look for a pattern of behaviour," he said on Sunday.

Iraq's press said on Monday Baghdad would cooperate fully with the inspectors, but urged them to be neutral and honest.

"We are keen to make their mission successful more than anybody else in order to expose the lies of U.S. and British governments," said Babel, the newspaper owned by President Saddam Hussein's eldest son Uday.

"We want these (inspection) teams to prove to the Americans that our country is free from weapons of mass destruction," the paper said in a front-page editorial.

SUSPECT SITES

British Foreign Secretary Jack Straw said in Brussels before a European Union ministerial meeting: "The ball is in Saddam Hussein's court. It is up to him now whether he is disarmed peacefully or by other means."

"We do recognise he (Saddam) has a degree of common sense and an instinct for survival and he knows what the situation is and what the consequences will be of his failure to comply (with the U.N. Security Council resolution)," he said.

In 1998, the United Nations lost patience with what it saw as Saddam's lack of cooperation after his defeat in the 1991 Gulf War  and pulled its inspectors out.

Backed by threats of a U.S.-led war if there is a repeat of 1998, Blix said on the eve of the visit that the weight of deciding if there should be war or peace with Iraq did not rest on his shoulders.

"We will report cooperation and lack of cooperation," Blix told reporters in Larnaca, Cyprus, where the inspectors have set up their logistics base.

"The question of war and peace remains first of all in the hands of Iraq and the Security Council and members of the Security Council," the 74-year-old Swede added.

IAEA chief ElBaradei said the inspectors would arrive in Baghdad with some knowledge of suspect sites because of tips from U.S. and other intelligence agencies as well as their own advance investigations.

"We have a very good game plan," he said.

When asked how sure he would be that Iraq was not concealing weapons, ElBaradei, an Egyptian, replied: "We do not take 'no' for an answer. We have to verify a 'no' is actually a 'no'."

He said Iraq's reward for full access and a clean report was "to come back to be fully members of the international community and to eventually eliminate sanctions".

DECEMBER 8 IS FIRST BIG TEST

Blix said laboratories to be set up by his first team would test air, water and soil samples. Initial tasks would even include cleaning out the long-vacant U.N. offices with vacuum cleaners the group brought along.

Blix said nothing will be off-limits including mosques and Saddam's palaces.

The first significant test is a December 8 deadline for Iraq to submit a full account of all its banned weapons programmes. By January 27 next year, the inspectors must have given their first report to the U.N. Security Council.

Sunday's bombing raids by U.S. and British warplanes were part of a rise in the number of incidents involving the patrols over no-fly zones in northern and southern Iraq as the chances of war loom over inspections.

Iraq does not recognise the no-fly zones, set up after the 1991 Gulf War, which drove Iraqi invasion forces out of Kuwait, to protect a Kurdish enclave in the north and Shi'ite Muslims in the south from attack by Saddam's military.

PHOTO CAPTION

Chief U.N. weapons inspector Hans Blix (R) and director of Vienna-based International Atomic Energy Agency Mohamed ElBaradei (L) prepare to board a U.N. C-130 transport aircraft at Larnaca, Cyprus international airport on November 18 headed for Iraq. REUTERS/Yannis Behrakis