The identity of the fourth bomber involved in the London attacks has been indicated by police sources.
Forensic experts were searching the house and garden
He is said to be Jamaican-born Lindsay Jamal, also known as Germaine Lindsay, who is understood to have lived in a house in Aylesbury searched by police.
In Aylesbury, neighbours said the occupants of the house were a couple with a young child who had rented the property for about six months.
Mr Jamal is believed to have died in the Russell Square bomb attack.
Police sources have said formal identification could take some time because it is likely to involve DNA analysis.
Police did not find any explosives in the house in Aylesbury which was raided by officers on Wednesday.
Neighbours said the occupants were a couple with a young child
One neighbour said: "They are a couple, a black man in his early 30s and a woman in her 20s who has converted to Islam. They have a little boy who's about 18 months old.
"They moved into the house about six months ago. They were just about to renew the contract, I think."
Joao Lima, 55, who lives two doors down from the house being searched, said: "There is a European lady living at the house. She dresses in Islamic clothes."
At a press briefing in Aylesbury Civic Centre, Peter Neyroud, Chief Constable of Thames Valley Police, declared his support for the Metropolitan Police in their investigation following the London bombings.
The raid was in connection with the London bomb attacks
He said: "As I'm sure you will understand, this is a Metropolitan Police investigation so it would be inappropriate to discuss any element of it."
Referring to the house raid in Aylesbury, Mr Neyroud added: "This development shows that terrorism is not something that happens to other people, is not something that develops in large cities but can happen in rural Buckinghamshire.
"This is why it is so important for all of us to be alert, play our part and work together to conquer these criminals."
'God is not blood-thirsty'
Abdul Dayan, imam at Aylesbury Mosque, condemned the terror strikes.
"No religion on earth condones such violence. I do not believe in a God that is blood-thirsty, especially for those whose blood is innocent," he said.
"My prayers are with those who have left this world in such a terrible way."
In West Yorkshire, home to at least three of the suicide bombers, police were on Thursday targeting another house.
Across Britain there was a two-minute silence to remember the victims of last week's bombings which left at least 49 dead.