Britain's main anti-war group, the Stop The War Coalition, said marches were being staged in at least 20 cities from midday (1200 GMT) as a way of "expressing mounting anger at the news of the rising civilian casualties".

A rally was planned outside BBC television offices in London as part of a campaign for more media coverage of deaths and injuries to civilians.

Stop The War Coalition spokeswoman Ghada Razuki told AFP: "We've been inundated with complaints about the biased reporting of the BBC. They are just following completely the government line."

Prime Minister Tony Blair has been Washington's staunchest ally in the US-led war.

According to Iraq Body Count, a group of British and US academics and researchers who provide a toll compiled from online media reports, between 283 and 391 civilians have been killed in the war in Iraq since it began on March

As well as London, demonstrations were planned in scores of towns and cities, including the Scottish capital Edinburgh, Southampton on the southern English coast, Birmingham and Coventry in central England, Cambridge in the east and Manchester in the northwest.

Meanwhile, Defence Secretary Geoff Hoon was expected to attend a ceremony to mark the return of the dead British soldiers at a base in Brize Norton, west England, home to the Royal Air Force's tanker and transport fleets.

The bodies of eight British servicemen who died when the US Sea Knight helicopter they were aboard crashed south of the Kuwait border, were among the first 10 to be brought back.

The other two bodies were those of the crew of the British GR4 Tornado warplane which was hit near the Kuwaiti border by a US Patriot missile.

A British military spokesman on Saturday denied media reports that up to five British soldiers had been captured in the southern Iraqi city of Basra, saying that no British troops had gone missing overnight.

But the defence ministry said one British soldier was missing, presumed dead, and four others were injured in a separate incident apparently involving friendly fire. If the soldier was confirmed dead, he would be the fifth British friendly fire casualty since the war began 10 days ago.

Britain's Press Association reported that the soldier was killed after a US A10 tankbuster plane targeted two armoured vehicles near Basra but the defence ministry said it was still investigating the circumstances.

The incident brings to five the number of British soldiers who have been killed by friendly fire since the US-led war on Iraq began on March 20.

On March 23, a US anti-missile Patriot missile shot down a British Tornado bomber, killing both pilots on board.

On March 24, two soldiers were killed when a British Challenger tank mistakenly opened fire on another Challenger tank.

A total of 23 British soldiers have so far died in the conflict, including 14 as a result of helicopter accidents and four killed in action.

Separately, the Daily Mirror tabloid reported on Saturday that the number of British troops serving in the Gulf could be cut dramatically from 45,000 to 5,000 if the US-led war against Iraq drags on for at least six months.

WAR.WIRE