- One suspect is described as a white boy, with blond hair and blue eyes, approximately 5ft 6ins tall and wearing a black woolly hat, dark jacket and grey tracksuit bottoms
- The other two suspects are both described as black boys, one approximately 5ft 2ins tall and the other approximately 4ft 11ins tall
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In a wide-ranging Peston on Sunday interview, he said Parliament security needs reviewing and the PM's counter-terror strategy is flawed.
The terror attack carried out by Khalid Masood at Westminster that left four people dead lasted less than two minutes say police.
Two knives were found at the scene in Islington, North London, and the suspects fled on foot before being arrested.