In this question, I asked justification for tatbir (Striking oneself with sword) and Matam (Self-flagellation) in Shi'ite sect. The answer I received is that tatbir and any kind of harming to body is declared haraam (prohibited) as it is harming oneself by Shi'ite scholars with some links to authentic Shi'ite resources. In one of those links, I found a fatwa which does not clearly call tatbir haraam rather it says " must be avoided since enemies of islam would not understand it ".
To quote the fatwa:
"Q1: I have a question about blood matam or what is known as Qama zani or Tatbir? What is your ruling about using blades, knives, swords and spilling blood during mourning rituals? Is it permissible?
A2: The philosophy of mourning during 'Ashura, is to respect the symbols of Religion and remember the suffering of Imam Hussain (a), his companions, and his uprising to defend Islam and prevent the destruction of the religion by Bani Umayyad dynasty. These rites must be done in such a way that in addition to serving that purpose, it draws the attention of others to these lofty goals. Obviously, Qama Zani does not have such a role and the enemies of Ahlalbayt misuse it. So those actions which are not understandable for the enemies of Islam and causes misunderstanding and contempt for the religion must be avoided. "
I do not see any mention of it being haraam (prohibited) because it causes harm to oneself here.
and one more :
Q2: It so happens that people beat their chests and their backs with chains and their bodies turn red and even start bleeding. Is it permissible?
A2: It is permissible and even preferable provided that it does not cause significant harm to the body.
It says beating until bleeding starts is preferable.
§ Question : What is the ruling on beating our backs with chains only during Muharram rituals?
§ Answer : It is permissible.
Is tatbir or extreme mourning by beating the back using chains a issue of difference of opinion among the Shi'ite scholars or is it unanimously declared haraam?