Scotland Yard said two passengers still remain trapped on the bus and two uniformed police officers who were travelling on the bus, are among the 30 injured.
London Ambulance Service say 6 people are seriously injured.
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Muslim leaders condemned the "heinous and appalling" Westminster terror attack.
Travis Frain is recovering in hospital and has posted a photo to Twitter of Prince Charles by his bedside.
Acting Commissioner Craig Mackey led new policemen and women in paying their respects at a passing-out parade in Hendon, north-west London.