Hundreds of people have been arrested in a 48-hour city crackdown on drink and drugs offences.
22 venues were temporarily closed, including a popular club in Brick Lane, which was shut by police following the arrest of several suspected drug dealers.
Edward Baran has the story:
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The 24-year-old was unarmed and the incident is not being treated as terror-related.
Some platforms have been taken out of service with disruption expected to continue until the end of the day.
The Met Office has extended its weather warnings for snow and ice to cover vast swathes of the country, including London and the South East.