Senior officials at the Pentagon say US and British forces have been attacking Iraqi military installations in an aggressive shift in strategy in the no-fly zones over the country.
The no-fly zones are not sanctioned by the United Nations
The strikes, which are being seen as a further stage in the preparation for war, have focused on rocket launchers and other weapons in the south which could be used against Allied troops if an invasion were to take place.
The no-fly zones - which have never been sanctioned by the United Nations - were imposed by the US, Britain and France after the 1991 Gulf War, in what was described as a humanitarian effort to protect Shia Muslims in the south and Kurds in the north.
Downing Street insisted however that its pilots were continuing to act in a defensive not offensive capacity - and that their actions were sanctioned by the United Nations.
"They respond to threats they encounter," said the prime minister's spokesman.
News of the strikes came on the heels of warnings by Iraq that it would cease co-operation with weapons inspectors if the US continued to move towards war without the backing of the United Nations.
Iraq destroyed six more banned Al-Samoud II missiles on Monday, bringing the total in three days to 16.
Established 1991 by US, France, Britain
France no longer participates
No explicit UN backing
Baghdad says hundreds of civilians have died in attacks
It also destroyed two empty warheads, the UN said.
Baghdad has also pledged to submit a detailed report before 10 March on what happened to its stocks of anthrax and VX agent, UN officials said.
In other developments
A team of Russian officials fly to New York to present the UN Security Council with an offer to provide assistance to weapons inspectors in Iraq.
- Gulf ministers fail to endorse a proposal by the United Arab Emirates calling for Iraqi President Saddam Hussein to step down to avoid war
- French President Jacques Chirac, who has taken a strongly anti-war stance, says Iraq must show more co-operation with UN weapons
- The Turkish Government says it is discussing whether to seek a second vote on allowing US troops into the country, after parliament rejected a motion on the issue
- French Foreign Minister Dominique de Villepin tells the BBC that France will oppose a second UN resolution on Iraq
Iraqi presidential advisor General Amir al-Saadi said Baghdad had now dealt with "practically all" of the UN inspectors' demands.
He said excavations at the al-Aziziya air base, about 104 kilometres (65 miles) south-west of Baghdad, had uncovered the remains of bombs containing anthrax, aflotoxin and botulin, which Iraq said it had unilaterally destroyed in 1991.
The general said eight of the bombs had been uncovered intact.
Iraq's failure to account for some 157 R-400 bombs, designed to deliver biological and chemical weapons, has been a key sticking point with the United Nations.
General al-Saadi also said 1.5 missing tons of VX gas and stockpiles of anthrax that were not put into bombs were also unilaterally destroyed.
He said Iraq knew where the destruction sites were and could carry out tests to prove the quantity of materials disposed of there.
After hours of technical discussions on Sunday night, the UN said Iraq had agreed to tell the UN in detail how it was measuring the amounts of VX nerve gas and Anthrax that was being dug up at these sites.
Iraq hopes UN Security Council will deem the methodology as correct, and thereby also accept that Iraq is free of chemical and biological weapons as it claims.
Tactical surface-to-surface ballistic missile powered by liquid fuel
Tested at range of 183 km - in excess of UN 150 km limit
Diameter also in excess of proscribed limit
May be able to deliver biological or chemical warhead
General al-Saadi said Iraq's destruction of its al-Samoud II missiles was an example of Iraq's "pro-active co-operation" with UN inspectors.
Iraq has about 120 al-Samoud II missiles, which the UN says breach range limits imposed after the 1991 Gulf War.
General al-Saadi said pictures of the destruction had not been released because it would be "too harsh" and "unacceptable" for the Iraqi people to see.