"What is clear is that Saddam Hussein's regime is coming to an end and that a better future is in sight for the Iraqi people," Hoon told a press briefing in London.

But resistance was "not necessarily at an end", Hoon added, as fighting raged in Baghdad following an advance by US troops into the heart of the Iraqi capital.

"In Baghdad itself, as in other urban areas, coalition forces may well face a difficult and dangerous period of flushing out Iraqi forces, particularly the various groups of irregulars, thugs and fanatics who hang on to the coat tails of the regime," the defence secretary said.

Updating parliament later on Monday on the Iraq campaign, to which Britain has contributed 45,000 military personnel, Hoon said US forces now controlled the major routes into and out of Baghdad.

"The pace of events over the past few days has been remarkable but it will take time for the Iraqi people to adjust to the rapidly changing circumstances," he said.

"We must all be patient, as there are many difficult and dangerous challenges lying ahead."

Hoon said US and British forces were "still not sure of the location of either Saddam Hussein or his sons", adding: "There are reports beginning to come in of the whereabouts of some of those three."

At his London press conference, Hoon said there was strong evidence that senior Saddam aide Ali Hasan al-Majid -- known as "Chemical Ali" for allegedly ordering a gas attack that killed about 5,000 Kurds in 1988 -- had been killed in a US-British air strike.

"We have some strong indications that he was killed in the raid conducted Friday night but I can't yet absolutely confirm the fact that he is dead. But that would be certainly my best judgement in the situation," Hoon said.

He added that protective equipment which had been found by coalition soldiers indicated that Iraq had weapons of mass destruction.

"Since neither the United States nor the United Kingdom has any kind of chemical or biological weapons, that protective equipment could only be designed to protect Iraqi forces against their own use of chemical weapons."

Hoon added: "We will find them. They are there."

He said British troops who had moved into the key southern city of Basra were there "to stay".

British forces now had access to all parts of the city and soldiers were being "warmly received by crowds of local people", he said.

A British officer earlier told journalists in southern Iraq that the battle for Basra was "more or less over", as thousands of troops poured in the city.

Hoon claimed the elite Republican Guard around Baghdad had been "reduced" by around 50 percent as US-led forces moved in on the capital.

"Many of those Republican Guard elements simply went home and we have found tanks in perfectly working order simply abandoned on the battlefield," he said.

"That indicates that many of those forces were not prepared to fight for Saddam Hussein. And once the threats and intimidation were removed they took a sensible course and abandoned their positions."

SPACE.WIRE