UK forces in Iraq have suffered their first combat loss with the death of a British soldier.
He was reported to have been shot during civilian rioting on Sunday near al-Zubayr, to the south of Basra, and died on Monday of his injuries.
The news came shortly before administration officials in Washington said Prime Minister Tony Blair was due to fly to the United States for talks with President George Bush later in the week.
Earlier on Monday it was reported that elements of Britain's Desert Rats - the 7th Armoured Brigade - were forced to withdraw from the vicinity of Basra in the face of unexpectedly fierce Iraqi resistance.
Meanwhile, efforts continue to locate and recover two other British soldiers missing in action since Sunday.
No details of Monday's combat fatality have been released, but military sources said next of kin had been informed.
A small number of British soldiers injured in hostilities in Iraq have been flown to a UK base on Cyprus.
Friday: 8 Royal Marines killed in helicopter crash in Kuwait
Saturday: 6 killed in helicopter collision in Gulf
Sunday: 2 Tornado crew shot down by US Patriot missile
Monday: British soldier killed in action in al-Zubayr
Details of the exact number of troops or the extent of their injuries have not been given.
The soldiers will be flown on from the Akrotiri base to the UK when their condition allows.
British troops have been involved in "extremely heavy fighting" around Basra and the port of Umm Qasr on Monday, according to the BBC's Caroline Wyatt at British forces HQ in northern Kuwait.
UK forces spokesman Colonel Chris
Vernon said UK troops about 5km (3.1 miles) west of Basra had exchanged artillery fire with Iraqi forces inside the city.
He said the defenders were regular army and about 1,000 "pretty determined" irregular militia, using guerrilla tactics such as wearing civilian clothes or faking surrender.
Elements of the 7th Armoured Brigade, including Challenger 2 tanks of the Royal Scots Dragoon Guards, pulled away from Basra early on Monday, according to journalist Simon Houston of the Daily Record.
Officers told him they were rethinking their tactics as they had underestimated likely resistance.
"We always had the idea that everyone in this area hated
Saddam. Clearly, there are a number who don't," said Captain Patrick Trueman.
But politicians and military leaders insisted the campaign was progressing well, despite "pockets" of resistance.
UK Prime Minister Tony Blair said the paramilitaries in Basra were hated by the local population and had little to lose.
"Basra is surrounded and cannot be used as an Iraqi base. But there are pockets of Saddam's most fiercely loyal security services who are holding out.
"They are contained but still able to inflict casualties on our troops and so we are proceeding with caution."
He said Basra airport had been secured.
The commander of 3 Commando Brigade, Brigadier Jim Dutton, said he was "very pleased" with the progress of his troops so far.
"It was inevitable that we would be slightly slower in some areas than we originally expected, and faster in others,
which has been the case."
The BBC's Paul Adams, in Qatar, said some reporting had given "terribly misleading" views of the conflict by focusing on specific incidents.
Elsewhere, British forces are also searching for the two soldiers who went missing in an attack on a convoy near Basra on Sunday.
They were involved in fierce fighting around the town of Al Zubayr, a few miles south west of Basra, when their Land Rovers were attacked by rocket propelled grenades.
Troops from the Black Watch Battle Group discovered thousands of
weapons, including two Al Harith anti ship cruise missiles, hidden in underground bunkers and arms storage sheds at Al Zubayr at the weekend.
In other developments;
- US Patriot missile commander apologises for "friendly fire" targeting of RAF Tornado and says measures introduced to prevent similar incidents
- Defence Secretary Geoff Hoon says ongoing fighting and landmine danger mean it could be several days before port of Umm Qasr is safe enough to land humanitarian supplies.