Downing Street has accused Baghdad of mounting a spin campaign over the issue of no-fly zones.

Officials rejected claims by Saddam Hussein that coalition aircraft had killed Iraqi civilians in a bombing mission to destroy surface-to-surface missile batteries that could target Western troops in Kuwait.

Number 10 said that intelligence services had conducted "extensive battle damage assessments" and found no evidence of the Iraqi claim.

The prime minister's official spokesman said Iraqi statements detailing civilian casualties had been "invented".

Several raids had been distorted by Iraq in a bid to gain public sympathy.

Downing Street said the public should not be taken in by Saddam's propaganda machine.

Claims by Baghdad made in June 1999 that a US plane had been shot down were false, as were statements on civilian deaths made in August 2000 and April 2001.

"It is important to put anything that comes out of Iraq through the deepest prism of suspicion," said the official spokesman, warning journalists they should beware of attempts at media manipulation.

Downing Street claimed the public should be wary of reports by journalists in Iraq because if they were critical of the regime they would be "kicked out of the country".

Geoff Hoon told the Commons yesterday that there had been no change in the no-fly zone policy but conceded there had been "more frequent patrols involving a broader range of aircraft".

"Surface to surface missiles are occasionally attacked if they pose a threat to coalition forces," added Number 10.

"In relation to civilian casualties, we will do what we can to ensure they are kept to an absolute minimum," said the spokesman.

The admission of the change in policy led to questions over its legality.

Paul Keetch, the Liberal Democrat defence spokesman, called on defence secretary Geoff Hoon to clarify the official position on surface to surface missiles and artillery batteries.

"As far as I am aware, it is not illegal for Iraq to possess such weapons, nor is it illegal for it to station them in the no fly zones. This is a significant change in policy," he said.

"What are these new targets? How are they being chosen? And what is the legal basis for this new action? Has the government taken legal advice on this issue, what was it, and what is the view of the solicitor general?"