He retreated into the room, which officials later said was considered a hostile act.

Under the rules, troops cannot fire at people unless they commit a hostile act or show intent.

The police resented elected crime commissioners and saw the moves to tie pay more closely to performance as a hostile act.

A senior police source described the letter as 'a hostile act' that would cause anger across the service.

To treat humanitarian delivery as a hostile act and to treat aid workers as combatants could not be deemed legal or legitimate.