Allied advance: British and American forces were surrounding the strategic city of Basra this morning after seizing Iraq's economically vital oilfields in the south of the country - the first objective of the US-led invasion.
The push to Iraq's second-largest city was led by an American armoured group supported by tanks of Britain's 7 Armoured Brigade, the Desert Rats, and troops from the Black Watch and 1st Battalion Royal Regiment of Fusiliers.
"On the way, they have seen a lot of evidence of large-scale Iraqi capitulation, evidenced by abandoned positions and items of equipment," Admiral Sir Michael Boyce, Britain's chief of the defence staff, said last night.
British troops from the helicopter-borne 16 Assault Brigade have secured the rich Rumaila oilfields after encountering what Sir Michael described as "determined resistance" from Iraqi forces. By last night, "all the key components of the southern oilfields" were safe, he said.
Earlier, American marines backed up by Royal Marine commandos took the port of Uum Qasr, 20 miles south of Basra, after being caught for at least two hours in an unexpectedly fierce firefight. Iraqi troops fought back with machine-guns and anti-tank fire before they were overwhelmed with the help of British artillery. At least 250 Iraqi prisoners were taken.
Challenger 2 tanks of the Desert Rats covered their western flank before driving north towards Basra. Harrier GR7 and US F-16 jets flew overhead, hitting key targets on the ground.
"Umm Qasr has been overwhelmed," Sir Michael said.
In the Safwan area, about 12 miles away, up to 50 Iraqi soldiers surrendered to American marines. Meanwhile, RAF Tornado GR4 bombers flew overhead, attacking the town of Kut on the river Tigris towards Baghdad, Sir Michael said.
Umm Qasr is militarily more important than Basra because it will be used as a port to ship in food and clean water from aid agencies and the military.
Basra's importance, as the biggest city in the south and a centre for Iraq's Shia population, is more politically strategic.
The port would be available for the supply of humanitarian aid as soon as the waterways were cleared of mines, Mr Geoff Hoon, the British Defence Secretary, said last night.
"Any attempt by Saddam Hussein to release oil into the Gulf and create an environmental disaster has been thwarted," he said.
Australian forces intercepted an Iraqi patrol boat filled with sea mines and other military equipment in the area of Khawr Abd Allah, a stretch of water in the approach to Umm Qasr, a spokeswoman for British forces in the Gulf said.
British military officers say the battle in the south will serve as a crucial signal to the rest of Iraq.
"What we are trying to do with the military action on the ground is to put huge pressure on the regime," said Col Chris Vernon, a British military spokesman in Kuwait.
"This is to say to the Iraqi people, and give a message to the regime, that you are propping up this final pillar of government and the southern half of your country doesn't want him. Think about that." Securing the oilfields in the south was also "absolutely crucial" to the operation and to protecting Iraq's economic future. "If they are destroyed it will take a huge time to regenerate," he said.
Royal Marines consolidated their control of the Faw peninsula, south of Basra, securing key oil installations.
Marines from 40 Commando took control of an oil pumping station and two oil platforms.
Military sources said they had been concerned that Saddam Hussein would order his men at the oil stations to flood the Gulf with oil. Marines were also trying to secure six important gas and oil separation plants on the peninsula.
American tanks came under fire outside the strategically important city of Nassiriya on the banks of the Euphrates yesterday after a rapid dash across more than 100 miles of desert from Kuwait.
Hundreds of armoured vehicles from the 3rd Mechanised Infantry Division, which had met barely any resistance as they swept up through the desert to the west of the Euphrates, came to an abrupt halt outside the heavily defended city.
The US forces are braced for a bloody battle for control of the city, whose capture will mark a significant milestone on the thrust to Baghdad more than 200 miles to the north.
Troops are expected to advance towards Baghdad on either side of the Euphrates once the city of 400,000 people is under the control of US forces.
The Iraqi attack will have come as no surprise to commanders of the "Mech" because Nassiriya is crucial to the Iraqis. Lying on the banks of the Euphrates, it controls a series of crossings over the river.
It is also an important base of the southern Iraqi command, which is controlled by Gen Ali Hassan al-Majid, known as "Chemical Ali" for his role in coordinating the campaign to suppress the Kurds in 1988, which killed 200,000 people. Most of Nassiriya's population are Shia Muslims, who are more likely to welcome the US troops because they attempted to rise up against Saddam Hussein after the 1991 Gulf war.
The military action outside Nassiriya came after hundreds of tanks advanced through the desert unopposed after crossing the border through the night. In what was described as a "hard drive", which lasted around 12 hours, the tanks roared across the desert before crossing the main highway from Basra to Baghdad.
Iraqi drivers were said to have watched the tanks in amazement, according to journalists accompanying the forces. Gavin Hewitt, the BBC reporter with the Mech, said the tanks moved so quickly that fuel stops lasted no more than a few minutes.
The armoured vehicles advanced across the desert in columns, with air support provided by Apache tank helicopters. As they advanced, forces passed the wrecks of Soviet-made Iraqi tanks left half-buried in the sand after being destroyed in the 1991 conflict.
Mr Phillip Mitchell, the ground forces analyst at the International Institute for Strategic Studies, said that capturing Nassiriya would mark a significant point in the war.
"Nassiriya is a major administrative headquarters and is also Gen Majid's military district headquarters," he said. "It is a major strategic crossing point of the Euphrates. For all those reasons Nassiriya will be well defended, which will slow the Mech down for a while."
Mr Mitchell said that after seizing Nassiriya he expected US forces to advance on the eastern and western banks of the Euphrates as they pushed towards Baghdad. "I imagine that the 3rd Mechanised will go up the left bank of the Euphrates, while the 1st Marine Expeditionary Force will advance up the right bank." The quick dash across the desert was no accident, Mr Mitchell said. "The route will have been chosen knowing full what was in front from reconnaissance."
Mr Tim Ripley, of the Defence Studies Centre at Lancaster University, warned people not to get carried away by pictures of tanks thrusting across the desert. "We have not yet seen a major engagement between large groups of troops," he said. "Until you see that you just can't judge the willingness of the Iraqis to fight."
US forces bombed a military base near Kirkuk in northern Iraq early yesterday, inflicting heavy casualties on the Iraqi army, Kurdish officials reported.
Soon afterwards, American and British forces seized two important airfields in the western mountains of Iraq, gaining control of a site the Pentagon has suggested may be home to Scud missile stocks whose existence Saddam Hussein has long denied.
But reports that US special forces had already secured the massive northern oilfields at Kirkuk were denied by local Kurdish military officials.
But they confirmed that American warplanes had struck the huge Khalid bin Waleed base, 10 miles south of Kirkuk. "There have been many casualties inside the camp," Mr Kosrat Rasul Ali, the military head of the Kurdish enclave, near Kirkuk, said. The base was an obvious target for the US military.