More families are expected to receive confirmation that they lost a loved one in last week's London bomb attacks, following the first naming of a victim.
The attacks have so far claimed 52 lives
Police, who named Susan Levy, 53, from Herts, on Monday, have asked for patience as they deal with the "biggest crime scene in English history".
Police have searched four properties and are searching a fifth in the Yorkshire area in connection with Thursday's bombings.
The number of confirmed dead is 52.
Recovery efforts are continuing in the wreckage of a Tube train between King's Cross and Russell Square stations.
Conditions for recovery teams working on the remains of the damaged Piccadilly Line train, who have been dealing with asbestos risks, vermin, fumes and temperatures as high as 60C (140F), have eased.
This is because of the removal of the airtight seals around the site, which had been kept as a secure crime scene, BBC home affairs correspondent Rory MacLean said.
"Forensic evidence gathering has been going on alongside the removal of the victims," he said.
Work has been concentrated underneath the train because it is thought the position of the bomb on the floor of the carriage would have led to some of the victims ending up on the track, he said.
Only after the recovery of any remaining bodies and the forensic work has been completed will work begin to remove the train.
Metropolitan Police Commissioner Sir Ian Blair visited King's Cross on Monday to lay flowers and said officers would identify victims as quickly as possible, but warned the process could not be rushed.
"However terrible it is, we must take our time as we go through the identification process," he said.
In other developments:
Prime Minister Tony Blair promised one of the most "vigorous and intensive" police manhunts the UK has seen to catch those responsible for the bombings.
US President George W Bush described the bombings as "an attack on the civilised world".
Former UK Foreign Secretary Robin Cook criticised Mr Bush's approach, saying: "I think the problem... is that he does keep talking about it as a war on terror as if there is a military solution and there isn't."
US service personnel at two bases - RAF Mildenhall and RAF Lakenheath, in Suffolk, - have been banned from entering London in the aftermath of the bombings.
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The police vowed to deal "robustly" with any racist attacks in the wake of the bombings. Met Deputy Assistant Commissioner Brian Paddick said there was evidence of revenge attacks on Muslims.
The Mayor of London, Ken Livingstone, announced the opening of a memorial fund, set up with the Red Cross, which has already donated £50,000 to help victims and their families.
Scotland Yard said a strong public response to the attacks was helping its inquiry.
Sir Ian appealed to the public to give investigators time, but vowed: "These people will be caught."
Anyone worried about relatives missing after the bombings is asked to call 0870 156 6344.
The anti-terrorist hotline is also available on 0800 789 321.
Between Aldgate and Liverpool Street tube stations
Between King's Cross and Russell Square tube stations
At Edgware Road tube station
On bus at Tavistock Square