Police in London are still searching a flat in the north of the city which they think was used by the four men who attempted last week's attacks.
They now believe that the contents of the rucksacks used last Thursday were made in the flat.
Police are also searching a nearby underground car park and have seized a Volkswagen Golf car a short distance away in Finchley which they think may have been used by the would-be bombers.
More information has also emerged on two of the would-be bombers.
24-year old Yasin Hussan Omar, the man seen fleeing from Warren Street Station, is a Somali asylum seeker who came to Britain in 1992 and was later granted indefinite leave to remain.
Another suspect, 27-year-old Muktar Said Ibrahim, who attempted to bomb a London bus, came from Eritrea 13 years ago, also as an asylum seeker, and was issued with a British passport last September.
Detectives think they could be looking for at least five suicide bombers.
Blair contrasts attacks with IRA campaign
As the search continued, the British Prime Minister, Tony Blair, met opposition leaders at Downing Street to discuss tough new anti-terror legislation.
The British Parliament will begin debating the proposals in autumn.
Mr Blair says what London faces today is different to the IRA's bombing campaign in Britain.
At a news conference after the meeting, he said that the willingness of these suspects to kill without limit made them an appreciably different threat to that posed by the IRA.
He also said Britain should 'not give an inch' to suicide bombers and that there was no justification for the recent attacks on London or suicide bombings elsewhere in the world.
He said that the political demands of the bombers now attacking London were none that any serious person could negotiate on.
He also denied ever saying that the attacks 'had nothing to do with Iraq'.
It emerged this morning that, according to an opinion poll in today's London Times, Mr Blair's popularity rating has soared, even though a majority of voters believe Britain's involvement in Iraq has increased the likelihood of attacks on London.
Meanwhile, senior police have said they will not alter their policy of shooting suspects in the head in the hunt for suicide bombers.
Reports say the strategy of firing more than one bullet into the head is based partly on experiences in Israel, Sri Lanka and Chechnya.
