Witnesses recounted seeing the suspects — armed with meat cleavers and possibly a firearm — rushing toward police when officers arrived on the scene. Police then opened fire.
Images from the scene showed a blue car that appeared to have been used in the attack, its hood crushed and rammed into a signpost on a sidewalk that was smeared with blood. A number of weapons — including butchers' knives, a machete and a meat cleaver — were strewn on the street.
The Associated Press examined the footage to verify its authenticity, cross-referencing images from the scene, aerial shots, the location of a car behind the alleged attacker and the appearance of a body and a car in the background. There was no immediate way for the AP to verify who the cameraman was.
Other images showed the second suspect clutching a long knife as he engaged in conversation with a woman who British media said tried to intervene to prevent further bloodshed.
The Daily Telegraph identified the woman as Ingrid Loyau-Kennett, 48, and said she confronted the attackers, telling them: "It is only you versus many people. You are going to lose."
Police defended the speed of the department's response to the attack.
In a statement, Assistant Commissioner Simon Byrne said police were on the scene nine minutes after receiving the first emergency call. Once it became clear that firearms were involved, firearms officers were called and arrived 14 minutes after the first call to police, he said.
Britain has been at the heart of several terror attacks or plots in recent years, the most deadly being the 2005 rush-hour suicide bombings when 52 commuters were killed. More recently, Parviz Khan was convicted in 2008 of plotting to kidnap and behead a British Muslim soldier in Birmingham.
Late Wednesday, riot police fanned out in Woolwich as about 50 men waving the flag of the far-right English Defense League gathered, singing nationalistic songs and shouting obscenities about the Quran.