Indians on the Western Front in France

I watched some footage of Indians on the Western front in France with the British army. I picked this clip because I had no idea that Indians had anything to do with the Great War. One tribe in the clip, the Sikhs, were seen building trenches, operating machine guns, and dancing around. They had their own regiments, but still got to go out into combat like the rest of the soldiers. One thing that the Indians would do a lot in the clip was build things such as periscopes in workshops. They seemed to be doing more manual labor than any other soldiers. The fact that native Americans were helping in the war not only in the shops, but in the battlefield as well as very interesting. http://www.oucs.ox.ac.uk/ww1lit/education/pathways/path/kd7bq7/16