U.N. weapons inspectors in Iraq said they found empty rocket warheads designed to carry chemical warfare agents, but a U.S. official said the discovery did not amount to a "smoking gun" that could trigger war. Iraq, which marks 12 years since the Gulf War on Friday, insisted it had declared the weapons casings to the United Nations last month. It was not clear whether the warheads had ever contained banned chemicals, but the experts took samples away for testing.

President Saddam Hussein, who faces massed U.S. forces prepared to oust him if given the go-ahead, was due to deliver a televised speech on Friday to mark the anniversary of the 1991 conflict, sparked by his country's invasion of Kuwait.

The Iraqi News Agency said Saddam would begin his speech at 11 a.m. (0800 GMT).

A new military intervention could be triggered if the inspectors find sufficient evidence that Saddam is breaking vows made after the Gulf War to give up chemical, nuclear and biological "weapons of mass destruction."

But the U.S. official, speaking on condition of anonymity, said the latest discovery did not amount to that: "A smoking gun would be if you found a big stockpile with chemicals."

U.N. spokesman Hiro Ueki said in Baghdad inspectors had come across the warheads during an inspection of bunkers built in the late 1990s at the Ukhaider Ammunition Storage Area, 120 km (75 miles) south of the capital.

DIPLOMACY INTENSIFIES

All sides earlier agreed war was not inevitable although Washington has expressed increasing impatience with Baghdad.

U.N. weapons chief Hans Blix, due in London on Friday as part of a diplomatic tour ending in Baghdad on Sunday, said Iraq must prove it has destroyed banned weapons to defuse what he called a "very dangerous" situation.

Russia, which holds a veto on the U.N. Security Council, stepped up its diplomatic efforts to avoid war by sending Deputy Foreign Minister Alexander Saltanov to Baghdad.

Saltanov's boss, Foreign Minister Igor Ivanov, said on Thursday he was worried about what he called growing pressure put on the inspectors by certain circles in Washington. Members of the U.N. team insist they are acting independently.

White House spokesman Ari Fleischer said President Bush has not made a decision about whether to go to war but called January 27 when Blix and ElBaradei are due to brief the U.N. Security Council "an important date."

"Beyond that events will dictate timetables," he said.

Blix said he was "almost sure" diplomats would request another report in February.

But EU foreign policy chief Javier Solana said Blix told him the time for inspections was "not very long."

General Hussam Mohammad Amin, the head of Iraq's National Monitoring Directorate, said Iraq had declared the empty weapons casings found on Thursday to the United Nations last month.

"These rockets are expired...they were in closed wooden boxes...that we had forgotten about," he said, challenging the United Nations to disprove that and calling it a "storm in a tea cup."

U.N. arms experts on Thursday also visited the homes of two Iraqi scientists in Baghdad, the first visits of their kind.

Inspectors complained again that Iraq has failed to provide evidence of action it says it took to destroy stocks of banned weapons after previous U.N. teams left in 1998.

The experts returned after a new Council resolution, 1441, passed in November, which threatens "serious consequences" for non-compliance -- a phrase Washington interprets as meaning war.

Blix said inspectors found illegally imported conventional weapons materials, some dating from two years ago, but had not determined if they were destined for banned weapons programs.

He and ElBaradei said to avoid war; Iraq must be seen as not only cooperative but also "proactive."

"The message we want to bring to Baghdad is, the situation is very tense and very dangerous and everybody wants to see a verified and credible disarmament of Iraq," Blix said in Brussels where he met European Union officials.

Oil prices hit two-year highs after Blix's remarks, which renewed fears of a big supply crunch if war cuts Iraqi exports

PHOTO CAPTION

Iraqi television footage shows a U.N. weapons inspector standing over one of the empty warheads said by the U.N. to be designed to carry chemical warfare agents, at the Ukhaider Ammunition Storage Area 75 miles south of Baghdad on January 16, 2003. A U.S. official said the warheads did not represent a 'smoking gun' that could mean war. (Re