title: Unable to delete docker image of a running container using -f option
body: <p>I tried to create a container using the following</p>
  
  <pre><code>docker run -it centos bash
  </code></pre>
  
  <p>and exited without killing it.</p>
  
  <p>Now I'm trying to delete the centos image using its image ID.</p>
  
  <pre><code>docker rmi -f 0f3e07c0138f
  Error response from daemon: conflict: unable to delete 0f3e07c0138f (cannot be forced) - image is being used by running container a9eab034a426
  </code></pre>
  
  <p>On docker documentation <a href="https://docs.docker.com/engine/reference/commandline/rmi/" rel="nofollow noreferrer">page</a>, it says " You cannot remove an image of a running container unless you use the -f option." but still I'm unable to remove image using -f. What can be the explanation for this? Should there a correction in documentation?</p>