Iraqi President Saddam Hussein has issued a rallying call to what he called the "brave and heroic" Iraqi people in a broadcast on national television.
The Iraqi leader, dressed in an olive green military uniform and reading from a script, promised that victory over US and British forces was near.
His speech - only the second he has made since the outbreak of war - came as US-led forces continued to close in on Baghdad in the face of some fierce Iraqi fighting.
US military commander, General Tommy Franks, said the coalition forces were making "rapid and, at times, dramatic progress", and described the Iraqi resistance as "sporadic".
Iraqi TV has shown pictures of an American Apache attack helicopter which it said had been shot down near the town of Karbala, about 80 kilometres (50 miles) south of the capital.
The US military has confirmed that one helicopter is down. It has not commented on Iraqi reports that a second helicopter was hit and two American pilots taken prisoner.
American helicopter gunships were involved in a three-hour battle with a division of Iraq's Republican Guard at Karbala on Sunday.
US troops have meanwhile intensified their assault on Nasiriya, where the bridges across the Euphrates river are essential for troops moving north towards Baghdad.
The BBC's Andrew North, who is travelling with the US soldiers, says a large column of armoured vehicles is moving into the town, covered by artillery fire.
Further south, British forces have fired artillery into Iraq's second biggest city, Basra, in what they said was a response to Iraqi attacks.
In the north, US warplanes have been bombing Iraqi positions near Chamchamal, a frontline town controlled by Kurdish forces.
After a night of heavy bombardment, the capital Baghdad came under fresh attack on Monday afternoon. Reuters news agency reported a series of six explosions in the east and south-east.
Saddam Hussein appeared on Iraqi television at 0800 GMT (1100 local time) to proclaim that Iraqi forces were inflicting losses on the US and UK forces.
"Victory will be ours soon," he said. "Iraqis will strike the necks as God has commanded you."
At one stage he read out a roll call of honour naming individual commanders and their locations, such as the southern port of Umm Qasr.
But UK Defence Minister Geoff Hoon said the speech was almost certainly recorded.
"Obviously analysis continues, but what I can say straight away is that those pictures were not live," Mr Hoon told a news conference in London.
There has been intense speculation about the fate of the Iraqi leader since the war began.
Coalition forces are continuing their push towards Baghdad after what the US military described as the toughest fighting so far on Sunday.
American forces are facing particularly stiff resistance in Nasiriya - where 10 soldiers are now known to have been killed in an Iraqi ambush.
Iraqi television showed pictures of the bodies of several American soldiers and their wrecked vehicles, and broadcast interviews with five captured survivors - one of them a woman.
The US reacted angrily to the TV footage, which was shown around the world by the al-Jazeera news channel.
Iraq's Information Minister Mohammed Saeed Sahaf on Monday said the prisoners would be treated according to the Geneva Conventions.
The minister also said Iraqi forces foiled an attempted US and British landing near Kirkuk, a key city in the northern oil fields.
The BBC's Jim Muir, who is in northern Iraq, says it is impossible to verify the Iraqi report.
In the south, heavy artillery was fired into Basra after British troops came under attack, Brigadier Andrew Gregory said.
The British accuse the Iraqis of placing their guns close to the civilian population.
The International Red Cross says it is still concerned about the humanitarian situation in the city, where water and electricity supplies have been disrupted since Saturday.
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About 40% of Basra's pumping capacity has been restored - but not enough to supply its two million inhabitants with clean water, an ICRC delegate told the BBC.
Meanwhile, the southern Rumeila oil fields, which on Friday had been pronounced "safe" by British and US troops taking them, were declared "unsafe" by US officials on Monday morning because of the presence of armed Iraqis in the area.
In other developments:
- Iraq says 62 civilians have been killed and more than 400 wounded in various cities in past 24 hours
- US military experts investigate what they say is a suspected chemical plant near the town of Najaf, about 160 kilometres (100 miles) south of Baghdad
- Syria condemns the deaths of five civilians, killed when a US missile hits a bus near the Iraqi border.
- The Saudi Shura Council, which advises the ruler of Saudi Arabia, has called for an immediate end to the war in Iraq
- US President George Bush says he expects a massive humanitarian aid programme for Iraq to begin within days.