Hijama is an Arabic name for wet cupping, where blood is drawn by vacuum from small skin incisions for therapeutic purposes. It's generally performed by Muslims as it is a form of medicine specifically mentioned and encouraged by the Islamic prophet Muhammad.
Hijama can be performed anywhere on the body, often at the site of an ache or pain in order to ease or alleviate it.
The pictures are taken in a clinic in Tehran.
More pics: 1, 2, 3, 4