Git : how to delete remote tag

How to delete remote git tag ?

git tag -d v1.1.1 
git push origin :refs/tags/v1.1.1 

how to bulk delete tags ?
check out the following links

https://gist.github.com/matthewmccullough/898798

http://blog.siyelo.com/how-to-bulk-delete-remote-git-tags