1. According to some reports, the tests are a response to ISIL's attacks in Tunisia, where at least 30 UK tourists were killed. The Metropolitan Police say the operation is part of the government's regular National Counter Terrorism Programme.
  2. Using #999exercise, police, emergency response units and media outlets shared updates:
  3. Many were sceptical about the exercises:
  4. Some took the emergency responses lightly:
  5. Others discussed social media's role in emergency situations:
  6. Many praised the organisations taking part:
Read next page