Inspections continued on Thursday, a day after Iraq blocked a UN team at the headquarters of the ruling Ba'ath Party in Baghdad. The UN arms inspectors are searching for banned weapons materials.

"All teams have gone out as usual. They are undertaking their full range of activities," UN Special Commission (Unscom) spokeswoman Caroline Cross said.

On Wednesday the official Iraqi News Agency said UN weapons inspectors tried to enter the offices in "a surprising and provocative manner".

It said the men were not refused access, but left when asked to present written confirmation of the purpose of the UN inspection.

The BBC's Jeremy Cooke: "Iraqis accuse the inspectors of provocation"

Mr Butler said: "This was an absolutely legal no-notice inspection and they blocked us. It was a blockage and it's wrong."

A UN spokesman in Baghdad described the Iraqi action as a serious development.

The move has been seen as a breach of Iraq's undertaking to allow weapons inspectors full and unfettered access to any site in the country.

Military strikes: Forces prepared

BBC Baghdad Correspondent Jeremy Cooke says that agreement was crucial in avoiding air strikes by the US and UK against Iraq in November.

White House spokesman David Levy warned Baghdad that the US was "poised to act" if Baghdad blocked the work of Unscom.

Thousands of US troops and hundreds of warplanes are on standby in the Gulf.

Butler report awaited

UN Correspondent Rob Watson: "So far the response from Washington and London has been muted"

However Washington is awaiting an Unscom report, due next week, on overall Iraqi co-operation.

BBC UN Correspondent, Rob Watson says there is a sense at UN headquarters that nothing much will happen until then and until the Clinton administration has decided exactly how it wants to handle this potential crisis.