Iraq has for the first time banned all United Nations flights into the country following four days of air strikes by the United States and Britain. "We have been informed by the Iraqi authorities of their decision to cancel all UN flights" to and from Iraq, a UN official in Baghdad said. What appeared to be a fresh stand-off began with reports that Iraqi authorities had banned a UN plane from landing near Baghdad, forcing UN special envoy Prakash Shah to leave the country by road. "A UN plane was expected in Habaniya airport to take envoy Shah but it was not allowed to land," a UN source said. Shah and UN humanitarian programme coordinator Hans von Sponeck had to leave by road for Amman for their Christmas holiday. The two had remained in Baghdad with a skeleton crew of humanitarian staff during the bombardment. This was followed by the cancellation of a scheduled flight of military observers monitoring the cease-fire and demilitarised zone on the Iraq-Kuwait border. Iraq offered no explanation for its decision, which was likely to increase tensions with the United Nations. The UN official, who spoke on condition of anonymity, said he hoped the measure was temporary and that the UN is pursuing the matter with Iraq. The flight had been scheduled to carry members of the United Nations Iraq-Kuwait Observer Mission, or UNIKOM, from Amman, Jordan, to Habaniya air base outside Baghdad, the official said. The force was set up after the 1991 Gulf War which evicted Iraqi forces from Kuwait following their seven-month occupation of the emirate. Another UN official said Syria also denied clearance for the flight, whose planned route would have carried it over Syrian air space. UNIKOM flights are routinely scheduled for Sundays and Wednesdays but were halted last week due to the US-British military air strikes on Iraq. The four nights of bombardment ended on Saturday. Iraqi air defences are still on alert for further possible attacks and the cancellation of the UN flights may be the result of Iraq's fears of more air strikes. Iraq had warned Tuesday that it would not forgive Kuwait for allowing the United States and Britain to use its military bases to mount last week's air strikes. Meanwhile, UN humanitarian workers resumed normal duties yesterday after returning from Jordan. Their first task will be to judge the impact of the bombing campaign on the UN-approved oil-for-food programme and other international efforts to help the 22 million Iraqis, UN officials said. Benon Sevan, head of the humanitarian programme at UN headquarters in New York, ordered a survey taking no more than a week to determine what repairs are needed, the officials said. They said UN food observers also went out yesterday to check gain silos and aid distribution centres in Baghdad and elsewhere in Iraq. The Iraqi government also ordered an assessment of civilian and military losses from the US and British bombardment. Iraqi officials said the government intends to formally ask the UN Security Council for compensation. The ruling Baath party newspaper Al-Thawra said in a front-page editorial that the Security Council was required now "to condemn America and Britain and lift sanctions." Iraq on Tuesday accused US and British warplanes of firing two missiles towards the southern city of Basra, saying the renewed aggression was part of a policy "to harm Iraq." The Pentagon and the British defence ministry denied the claim. The Iraqi News Agency reported that three children were killed and 20 others wounded in the southern province of Wasit as a result of the US-British assault. The casualties would be in addition to the 62 soldiers and an unspecified number of civilians that Iraq claims were killed in the strikes. The United States says the air raids and 425 Tomahawk cruise missile strikes targeted 100 sites, mostly defence related, and were intended to reduce Iraq's ability to build weapons of mass destruction. With the future of the UN Special Commission [UNSCOM] clouded, the Clinton administration stood firm on keeping economic pressure on Iraq unless it got rid of its remaining chemical and biological weapons. Iraq must be prepared "to move toward disarmament" and not threaten its neighbours or the Kurds to get the sanctions lifted, Under-Secretary of State Thomas Pickering said. "It is up to UNSCOM to decide how it can be most effective in the pursuit of their mission," Pickering insisted. Iraq, meanwhile, has vowed that UNSCOM is "something of the past." A former member of UNSCOM accused Washington yesterday of having manoeuvred UN arms inspectors in Iraq into providing a pretext for the attacks on Baghdad. "I believe that this inspection was rushed through, and the sites weren't chosen for disarmament reasons, but rather to be provocative in nature, so Iraq would respond in a predictable fashion," Scott Ritter said. "That response would be used as a justification for military actions." At the UN the Security Council, putting aside deep divisions over sanctions and weapons inspections, started on Tuesday discussing two less contentious steps to help map a new policy on Iraq after the US-British bombing campaign. On the table was a revised Russian proposal calling for Secretary-General Kofi Annan to submit "an overall assessment of the current situation on the ground in Iraq" and a meeting of the executive board that oversees the weapons inspectors. "Most members supported this approach today," said Russia's UN ambassador Sergey Lavrov, expressing hope that the Council would reach agreement soon "in order to get the ball rolling." Crucially, the United States did not oppose either step, although diplomats said Washington had some questions about exactly who would carry out the assessment.