Iraqi children celebrate death of four Britons: And the war is going well?

Four soldiers, two of them women, died when a huge bomb hit their patrol in Iraq.

A child holds a piece of wreckage left behind after a roadside bomb exploded

As the 15 sailors and Marines, including Leading Seaman Faye Turney, prepared to board their plane home from Tehran, Iraqis were dancing around a 3ft crater in the road near Basra, brandishing grisly ' souvenirs' including a soldier's helmet.

All the soldiers who died were in a Warrior armoured vehicle shattered by a devastating explosion. One of the women was from the Royal Army Medical Corps, the other from the Intelligence Corps.

A Jordanian interpreter was also killed and a fifth soldier was fighting for his life last night.

Tony Blair stopped short of directly pinning the deaths on Iran, but accused the Tehran regime of "financing, arming and supporting" attacks on UK forces.

A crater is left where a roadside bomb exploded in Basra, killing four British soldiers and a Kuwaiti interpreter

Britain and America have repeatedly blamed Iran for supplying the special armour-piercing bombs and triggering mechanisms used by Iraqi insurgents.

Mr Blair said: "Just as we rejoice at the return of the 15, so we are also grieving and mourning the loss of our soldiers in Basra.

'On the one hand we are glad that our service personnel are returned from their captivity. But on the other we return to the sober and ugly reality of what is happening through terrorism in Iraq."

For both the Government and the hostages' families, yesterday had been full of promise.

But news of the Basra deaths - six British soldiers have now been killed in six days - quickly overshadowed the joy of the captives' return.

It also emerged that some of the captives may have been held in solitary confinemtne by the Iranians, Marines' spokesman Lieutenant Colonel Andy Price.

He said: "There were times when they were left alone, but we will not go into any further detail until tomorrow."

The 15 personnel from HMS Cornwall touched down at Heathrow - they swopped their shiny, Iranian suits for fresh uniforms on the British Airways plane - carrying bizarre 'goodie bags' from Ahmadinejad containing CDs, pistachio nuts and sweets.

Local people gather to collect macabre mementoes left at the scene

They were whisked by helicopter straight from the airport to the Royal Marines base at Chivenor in North Devon, for an emotional reunion with their families.

Amid tears, hugs and kisses, Leading Seaman Faye Turney - the 26-year-old sailor singled out by Tehran's propagandists - gleefully pulled her threeyearold daughter Molly into her arms.

But news had already emerged of the carefully planned attack near Basra.

It came at 2am as a column of Warriors was returning to base after a counter-insurgency search in the slum district of Hayaniya.

One vehicle was caught in a blast thought top have triggered by remote control.

Almost immediately a number of shells buried under the road were also set off.

The 20-ton Warrior was blown into the air and onto its roof.

One of the men who died was also from the Royal Army Medical Corps and the other from the 2nd Battalion The Duke of Lancaster's Regiment. Their next of kin have been informed of their deaths but their names had not been released last night.

Another UK soldier is being treated at the British military hospital at Basra Air Station, and was said to be in a 'very serious' condition.

The Defence Ministry denied reports that the British patrol had earlier arrested an Iraqi police officer. But they did not dispute claims that UK troops immediately surrounded a nearby Iraqi police checkpoint and arrested all the men there.

Basra police have been heavily infiltrated by Shia militia fighters who exploit their uniforms to carry out murders, kidnappings and extortion.

The deaths, following the killings of two soldiers by snipers, made it the worst week for UK fatalities in Iraq in more than two years. It brings the total death toll to 140 since the 2003 invasion.

Four British servicewomen have now been killed on operations there.

Tory MP Patrick Mercer, a former infantry commander, said last night: "This is the reality of the smile on the face of the Iranian tiger. What the Iranians have delivered with one hand they have taken away with the other."

The Basra horror added to the pressure on Mr Blair amid accusations that Britain has been humiliated by the outcome of the 14-day hostage crisis. He faced calls to make an emergency statement in Parliament as concern mounted about how the two Navy boat teams came to be seized and the Government's subsequent handling of the incident.

Tories said there were serious questions to answer about operations in the Gulf and the level of support given to troops patrolling the area.

The Prime Minister again insisted no deal had been struck with Iran.

Government sources firmly rejected claims from a senior aide to Iran's supreme leader, Ayatollah Ali Khamenei, that Britain had sent a letter of apology before the Navy personnel were set free.

Margaret Beckett was also under fire for her "hapless" handling of the crisis. The Foreign Secretary was brutally sidelined as the drama reached its endgame, when Downing Street seized control of talks with the Iranians. • The bodies of two British soldiers killed earlier this week, Kingsman Danny Wilson, 28, of the Duke of Lancaster's Regiment and Rifleman Aaron Lincoln, 18, of the 2nd Battalion, The Rifles, arrived back at RAF Lyneham in Wiltshire yesterday.