While British police continue to hold three men after last week's failed bombings in London, investigators say they're looking for many more suspects.
They say they believe al-Qaida-linked groups were behind the attacks.
Investigators are also pursuing leads suggesting last week's attacks -- when several bombs only partially detonated -- were connected to the suicide bombings earlier in the month that killed 52 people and the bombers.
The city's police chief says the search is concentrated on the bomb makers, the financiers, and on those who recruited and groomed the actual bombers.
The three suspects arrested are being held on suspicion in last week's attempted attacks, but police say they're still looking for four men seen spotted on surveillance cameras fleeing the scenes.