Police were called to a £1 million property in north London to break up a party after 600 people turned up. According to the Evening Standard, the event was advertised on Facebook by a friend of 17-year-old Christopher Seale. He didn't realise the information could be seen by anyone.
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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.