London's Metropolitan Police was last night facing the challenge of a new terrorist threat, as officers painstakingly analysed hours of CCTV footage of the east London area where a nail-bomb injured six people on Saturday.
Scotland Yard has also expressed fears that a racist bombing campaign could spread outside London. Police forces in areas that have substantial ethnic populations are being put on alert.
The victims of the Brick Lane bomb - all of Bangladeshi origin - have since been discharged from hospital.
The explosion happened exactly one week after the Brixton bomb, which injured 39 people, and the neo-nazi group, Combat 18, has admitted responsibility for both blasts.
The Metropolitan Police Commissioner, Sir Paul Condon, confirmed that police were treating the attacks as "unequivocally racist".
Asserting that those responsible would be brought to justice, Commander Mike Craik of Brick Lane Police said: "The people of London need to recognise we have caught the Mardi Gra bomber, we caught the terrorists from Ireland, and we will catch these people."
Commander Craik also paid tribute to the bravery of a member of the public who intervened. The anonymous motorist found the device and attempted to take it to the local police station, but it detonated in the boot of his car. He escaped with only minor injuries and it is believed that many more people would have been hurt or killed had his vehicle not borne the brunt of the blast.
There has, meanwhile, been anger among ethnic community leaders who feel the police did not do enough to protect people in the aftermath of the Brixton bomb. Mr Mark Wadsworth, of the Anti-Racist Alliance, told BBC Radio 4: "People are suspicious of the police. They have a long way to go to regain our confidence in the light of the Stephen Lawrence affair."
The Brick Lane area is home to one of the largest Asian communities in the UK.
The black MP for Bethnal Green and Bow, Ms Oona King - whose constituency includes Brick Lane - said: "I think whoever planted this bomb was obviously aiming to terrorise the local population, and in particular the black and Bengali community here."
She went on to express fears over the reaction of local communities to the attack. "The racists intended to spark a race war. I am concerned that in the East End of London we don't degenerate into a vigilante atmosphere with groups arming themselves and prowling around the streets."
Brick Lane, like Brixton, is regarded by local people as an area where good race relations have prospered despite the efforts of racist groups.