British tanks and infantry have encountered what one senior officer described as "serious opposition", writes Jack Fairweather, outside Basra
The siege of Basra began yesterday, with a night of intense artillery and aerial bombardment in and around the city as British forces began their advance into Iraq.
Battle groups belonging to the 7th Armoured Brigade moved into position around the city, taking over from an earlier American advance, and pushing northwards to surround the city.
With the US Marine tank divisions that had been first through breaches in the Kuwaiti border pulling out to join the main thrust of the American attack towards Baghdad, the siege of Basra has become a purely British operation.
They have encountered what one senior officer described as "serious opposition". During the early hours of Sunday morning the skyline was lit-up with flashes as the bombs fell to the north of Basra, and flares hung over the outskirts of the city to identify targets.
Near the airport, red tracer bullets could be seen striking Iraqi tanks and ricocheting off British squadrons engaged with Iraqi units defending the south of the city, whilst a Cobra attack helicopters fired a parting salvo of hellfire missiles at a nearby building.
A British soldier with the 1st Regiment Royal Fusiliers, standing beside the dark silhouette of his jeep, watched in awe and said: "Is that my heart pounding or is it just the sound of artillery falling?"
As of yesterday afternoon Basra had not fallen, with the air above the south of the city awash with plumes of smoke as British artillery strikes continued to pound targets.
The British push into Iraq had begun in the early hours of Saturday morning. Throughout the day the 7th Armoured Division advanced into Iraq on the two approach roads to Basra, Challenger tanks and armoured personal carriers stretched along its entire length.
Newly-liberated Iraqis stood by the side of the road but neither cheered nor waved. As with many of the British soldiers experiencing war for the first time driving slowly in convoy, the Iraqis appeared to have been silenced by the scale of the advance. One column of tanks along the main highway to Basra was stalled for several hours when a Challenger drove over a booby-trapped culvert, fracturing its hull but leaving the crew with minor injuries.
It was the only ordnance encountered during the advance - the threat of mines so far not materialising. "It's going to take more than a mine to stop us now," said one Challenger tank driver.
As evening fell forward units of the 1st Regiment Royal Fusiliers were driving past the husks of bombed-out Iraqi tanks in military complexes a few kilometres south of Basra, the wreckage from the opening bombardment of the war.
The convoy moved in single file through clouds of dust, with each vehicle darkened except for a single lighted chemical rod, to avoid enemy detection Although officers in charge of the Iraqi 51st Division surrendered on Saturday - in charge of a 10,000 strong force that held the southern approach to Basra - units from the division provided limited resistance as British forces swept north and eastwards around the city.
There was however a brief flurry of lighters in the night as celebratory cigarettes were lit following reports filtering through the radio that "Chemical Ali", the Iraqi general who had ordered the chemical attacks on the Kurds, had been killed nearby.
"If he's dead then that an act of justice which should tell everyone why we're here," said Maj Matthew Botsford, of the 1st Regiment, Queen's Dragoon Guard.
On the outskirts of the city, its lights shining through a break in an earthen rampart, the hulking forms of US army carriers belonging to units yet to pull back could be seen. "We're waiting for the Brits," said one voice with a deep southern accent. "No, we're waiting for you," came back the reply from the convoy. The moment of humour was lost almost at once when the words came through over the soldiers headsets, "we have a blue on blue" the code words for friendly fire.
It was reported that further up the road, an Apache attack helicopter had hit an M1 Abrams tank "They're getting trigger happy now," said one British soldier, and the eerily formal sounding term "fratricide" could be heard in the night.
While tank components of the Royal Fusiliers moved in to hold four strategic bridges leading to the city, advance forces continued their movement northwards, crossing the Shatt al-Basra waterway in the early hours of yesterday morning to within a few miles of the Iranian border.
With Basra almost surrounded British forces have begin laying siege to the city to allow it time to capitulate and avoid what a senior British officer described as the "worse case scenario" of urban warfare.
"We aim to sit tight and let them realise that there is no more help coming to them. We realise after Umm Qasr they have more fight in them than we expected," said the officer.
"We hope that they'll realise soon enough that now is the time to lay down their arms and surrender peacefully," he said.
Should the city surrender, elements of the Black Watch, a battle group within the 7th Armoured Division, will then accompany humanitarian relief into the city.
The Royal Fusiliers will continue to push north to secure the eastern flank of the main American advance on Baghdad.
Two remaining Iraqi divisions of the three entrusted with the defence of Basra are now stationed near the town of al-Qurnah, 80 miles north of the port on the banks of the Shatt al-Arab waterway. They are believed to belong to the 6th Armoured Division, which fought in the Iran-Iraq War, and are known to be a capable fighting force, and the 2nd Mechanized Division.
Yesterday, the first British forces were already encountering possible advance units belonging to the 6th Armoured Division as they took the bridge over the Shatt al-Basra.
Spotting a squadron of Iraqi tanks standing guard, an illumination flare was sent up, and orders given to fire if there were no immediate signs of surrendering.
A few seconds later, the Iraqi tank commanders emerge waving a white flag and the bridge, a vital breach-head for the road northwards was secured.
"It's not getting anyway easier as we go northwards," said the officer