One of the suspects -- the man who appeared holding a bloody cleaver in the images that rocketed around television and the Internet after the attack -- was identified as 28-year-old Michael Adeboloja.
"The point that the two suspects in this horrific attack were known to the security services has been widely reported," Prime Minister David Cameron said during a statement Thursday. "You would not expect me to comment on this when a criminal investigation is ongoing."
Adeboloja was born in Lambeth and grew up in east London, Sky News reported.
"He was a student at Greenwich University, but it is not clear what he was studying there," crime reporter Martin Brunt said. Already on Facebook there are comments from former pupils say that they went to school with him in east London.
Brunt said counterterrorism investigators were investigating a house in Lincolnshire believed to belong to Adeboloja's father, and another in Greenwich.
One of the suspects reportedly was stopped as he tried to leave the country to join al Shaabab militants in Somalia.
After the Cobra emergency response meeting, Cameron vowed the attack would fail in its goal of terrorizing Britain.
"The people who did this were trying to divide us," Cameron said "They should know something like this will only bring us together and make us stronger."
"One of the best ways of defeating terrorism is to go about our normal lives."
London Mayor Boris Johnson assuaged fears of more violence, suggesting the counterterrorism services believed the attack was a one-off.
"Everything I am hearing leads me to think that Londoners can go about their business in the normal way and we are going to bring the killers to justice," Johnson said.
Johnson also urged people not to blame the religion of Islam for the attack, despite the killers' statements.
"It is completely wrong to blame this killing on the religion of Islam," Johnson said, "but it is also equally wrong to try to draw any link between this murder and British foreign policy or the actions of British forces who are risking their lives abroad for the sake of freedom."
"The fault lies wholly and exclusively in the warped and deluded mindset of the people who did it."
We will never buckle to terror— David Cameron (@David_Cameron) May 22, 2013