- The woman, who was with a female friend, was attacked by three men who ran off towards Tottenham Court Road
- She is now being treated for serious facial injuries
- Police are keen to speak to anyone who may have been in the area at the time
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Pictures of today's events unfolding following a major security incident at the Houses of Parliament.
At least two people have died after a knifeman brought terror to the heart of Westminster.
The Cobra committee brings together government ministers with senior officials of the emergency services and security agencies.