How to set a Mercurial VCS build trigger for TeamCity that ignores label operations

I am trying to setup a build trigger for TeamCity using Mercurial as the VCS. Right now the trigger looks like:

+:/**

This trigger get fired when changesets are committed. However, I have TeamCity setup to tag each build in the VCS. The tagging process is firing the above build trigger so the build gets caught in a loop.

Can anyone suggest a VCS build trigger that will filter out the tagging process?