The first British servicewoman to die in action in Iraq was among five military personnel killed in Saturday's helicopter crash in Basra.
Flt Lt Sarah-Jayne Mulvihill was a Flight Operations Officer
Flt Lt Sarah-Jayne Mulvihill, 32, died with Wing Commander John Coxen, Lt Commander Darren Chapman, Captain David Dobson, and Marine Paul Collins.
Wing Commander Coxen, from RAF Benson in Oxfordshire, is the most senior British officer to be killed in Iraq.
Specialists have arrived from the UK to investigate the crash.
The investigators, from the Joint Helicopter Command air accident investigation unit, are examining the helicopter's wreckage to find out if reports suggesting that it was downed are accurate.
It is unclear why the helicopter went down on Saturday, but if enemy fire is found to be the cause of the crash it would be the first time a British military helicopter had been shot down in southern Iraq.
Senior commanders say that nothing had been ruled out, but it could have been brought down by small arms fire, rocket-propelled grenade or an anti-aircraft missile.
Flt Lt Mulvihill, also of Royal Air Force Benson, served as a Flight Operations Officer.
Lt Cdr Chapman, of the Royal Navy, was the commanding officer of 847 Naval Air Squadron based at Yeovilton, Somerset.
The 40-year-old was married with three children.
Capt David Dobson, 27, of the Army Air Corps, had been serving as a pilot with 847 Naval Air Squadron, based at Royal Naval Air Station Yeovilton.
And 21-year-old Marine Paul Collins, from Dawlish, Devon, served as an Air Door Gunner with 847 Naval Air Squadron.
He was also based at Yeovilton.
Tributes have been paid to the five who died.
Group Captain Duncan Welham, Station Commander Royal Air Force Benson, spoke highly of Flt Lt Mulvihill.
Tributes have been paid to the crash victims
"Sarah was one of the Royal Air Force's finest: courageous, upbeat and unselfish," he said.
"She was a dedicated officer who will be missed by us all."
And Colonel John McCardle, of the Royal Marines, said Paul Collins was "the epitome of what the Royal Marines represent".
"A fit, intelligent young man, he was totally professional in everything he did and enjoyed life to the full."
Prime Minister Tony Blair, speaking at his monthly news conference, offered his sympathies to the families of those on board and paid tribute to the "heroism, commitment and professionalism of our armed forces".
Newly-appointed Defence Secretary Des Browne made a statement about the helicopter crash to the House of Commons in which he confirmed that an investigation in the crash was underway.
Mr Browne also touched on the government's plans for an exit strategy.
"We are still committed to remaining in Iraq as long as we are needed and the Iraqi government wants us to stay, and until the job is done," he said.
Wing Commander John Coxen is the most senior officer killed in Iraq
Its official line remains that the five are missing, presumed dead.
Meanwhile, Iraqi authorities in Basra have agreed to formally resume co-operation with the British Army after relations had soured following a series of flare-ups.
The governor of Basra, Mohammed al-Waeli, announced on Sunday that security co-operation with the British would resume after it had been suspended for several weeks.