As the first contingent of UN arms experts landed in Baghdad, Chief Inspector Hans Blix said he warned Iraq that it had to provide ‘‘convincing’’ evidence to prove it no longer possessed weapons of mass destruction.Despite a show of unity on inspections, the US forced the 15-member Security Council to extend for only nine days the Iraq humanitarian oil-for-food plan after failing to get it renewed for three months rather than the usual six.Hans Blix, whose assignment could determine whether the US launches war against Iraq, told the UN Security Council on Monday that the advance team of 19 inspectors would begin work from Wednesday.Blix, who just returned from Baghdad with Mohamed El Baradei, head of the International Atomic Energy Agency, also said Iraqi officials told him they had no banned weapons. But they raised questions about the crucial declaration of chemical, biological and nuclear arms due on December 8 under the new Security Council resolution.‘‘I had the feeling they were going to try to put up a very substantial report, although they wondered if they had to include every detail of their chemical industry down to the production of plastic slippers,’’ Blix said.But on the critical issue of access to President Saddam Hussein’s palace compounds, Blix said Iraqi officials told him ‘‘that the entry into a presidential site or a ministry was not the same thing as entry into a factory.’’Meanwhile, Council members agreed to renew the oil-for-food program, which expired at midnight on Monday, until December 4 so negotiations between Washington and the other 14 nations could continue.The program allows Iraq to sell oil to purchase food, medicine and a host of civilian supplies to ease the impact of UN sanctions imposed after Iraq’s 1990 invasion of Kuwait.Among the goods US wants banned are global positioning scanning devices, equipment to jam radio intercepts and injectors to administer Atropine and large quantities of the drug which can be used to combat nerve gases, US Ambassador John Negroponte said. The US was also seeking to block large-scale imports of Cipro, an antibiotic used to treat anthrax infections, diplomats added. (Reuters)