Three Black Watch soldiers have been killed and eight injured in a suicide attack in Iraq.
British troops were controversially redeployed to Camp Dogwood
A vehicle was detonated at a Black Watch checkpoint, followed by mortar fire at around 1300 local time, Armed Forces Minister Adam Ingram said.
An Iraqi translator also died. Six of the injured are already back at base.
The 850-strong force has been attacked repeatedly since it arrived at Camp Dogwood, 20 miles from Baghdad, on Friday, after a request from the US.
The latest attack brings to 73 the number of UK military personnel deaths in Iraq.
The remaining two injured soldiers are expected to be released from hospital on Friday.
A Ministry of Defence spokesman said on Thursday night the next of kin of all three soldiers had been informed but the names of the dead men would not be released until Friday.
'Always knew there were risks'
A spokesman for Tony Blair said: "The prime minister's thoughts are with the Black
Watch and the families of the Black Watch."
After offering his own condolences, Mr Ingram said: "We always knew there were risks involved in this engagement."
Scotland's First Minister, Jack McConnell, said: "No words will be able to ease the pain of their terrible loss, but the thoughts of everyone in Scotland are with them."
But there was anger from the SNP, with leader Alex Salmond attacking the ministers responsible.
'Shock and grief'
He told the BBC: "There will be shock and grief across Scotland. But that will give way to a feeling of anger as we contrast the bravery of our
soldiers with the duplicity of the politicians who sent them there."
Referring to the rescue effort following the attack, Mr Ingram told the House of Commons: "US forces helped to provide urgent medical support at the scene of the incident, something for which I know our forces were grateful."
BBC correspondent Ben Brown said the deaths have left the battle group in a "state of shock".
He said: "It will have hit the regiment very hard - they are a very close Scottish regiment with a long and proud history."
Since British Black Watch troops arrived they have come under attack from mortars fired at Camp Dogwood.
The Black Watch turned back schoolchildren from their makeshift pontoon bridge
On Tuesday, Defence Secretary Geoff Hoon said he was "confident" Black Watch would be back in their base in southern Iraq within 30 days.
The battle group were sent to patrol new territory along the eastern bank of the River Euphrates in terrain that was not previously in their area of operations.
They expanded their operations in an attempt to stop rebels reaching Falluja.
On Thursday troops were building a pontoon bridge across the river.
The Black Watch soldiers turned back a group of Iraqi schoolchildren trying to cross the bridge, but later handed out leaflets to locals saying they were Scottish soldiers trying to bring peace to the region.
The Chief of Defence Staff, General Sir Michael Walker visited Camp Dogwood to be briefed on the attack by Black Watch commanding officer Lieutenant Colonel James Cowan.
The group redeployed comprised three companies of armoured infantry from the 1st Battalion The Black Watch, with some 500 men and 50 Warrior armoured fighting vehicles.
They are supported by a reconnaissance unit from the largely-Welsh Queen's Dragoon Guards, with around 100 men and 12 Scimitar armoured vehicles, and a 50-strong Royal Marine light infantry unit from 40 Commando.
The Black Watch, which traditionally recruits from Perthshire, Angus and Fife, is based in Warminster, Wiltshire.
Critics of the deployment have suggested it has dragged Britain deeper into the turmoil of post-war Iraq and was part of political manoeuvring by the American government during their campaign for re-election.