US
Several political parties suspended campaigning on Sunday
World leaders express solidarity with UK
Three assailants stabbed passers-by at random after smashing into pedestrians in a van
Frightened people were led away as police officers screamed at them to run
It was the diversity of London that stole my heart when I first came to the city
The additional measures followed a review of security at Windsor, the oldest and largest inhabited castle in the world
'His attack method appears to be based on low sophistication, low tech, low cost techniques copied from other attacks'
Statement comes a day after British interior minister said end-to-end encryption on messaging services is unacceptable
London attacker Khalid Masood sent an encrypted message via WhatsApp minutes before the attack
Police say Masood, 52, had numerous convictions for violent offences but none terrorism-related