Salman,
I will paste the similar questions that have been answered by the shia scholers:
Questions:
It is my understanding that the act of beating one's self in mourning for Imam Husayn a.s. with blades or otherwise, is allowed in Islam.
QUESTION(a)
But when this type of behavior leads non-muslims to believe
that the Shi'ah are barbarious and that their religion is based more on
emotion than reason, and it confirms their misconception about us that we are fanatics and zealots, can it still be considered allowed?
ANSWER:
A(a) The ritual of self-flagellation as part of the Muharram
observances has generated heated discussion amongst the scholars and
laity. For instance, around mid 1920's Sayyid Abu-l-Hasan Isfahani
in Najaf and Sayyid Muhammad Qazwini in Basra issued legal opinions
against this practise. A similar position was taken by Muhsin al-Amin.
They were rebutted by Abd-ul-Husayn al-Hilli and members of the Kashif
al-Ghita family. Two issues were of concern for the jurists - one is
that this ritual at times led to the loss of human life and second,
public perception of Shi'ism. Ayatullah Sayyid Ali Khamena'i made
this ritual of qame zadan (hitting the head with a knife) haram by
virtue of the harm it does to public image of Shi'ism. Also, Shaykh
Shamsuddin and most probably even Ayat. Fadlullah have issued legal
opinions similar to Ayat. Khamena'i. However, most of the prominent
jurists have a different opinion. For instance, Ayat. Gulpaygani and
Ayat. Araki allow the ritual of self-flagellation so long as there is
no fear of loss of life or causing injury to any organ of the body.
However, Ayat. Gulpaygani states that it is better to avoid this
practise based on precaution (ihtiyat). They all emphasize that the
commemmorative mourning ceremonies, that take different forms, must
be kept alive to preserve the vitality of the symbol of Imam
Husayn (a.s.). In all probability the legal opinions of Ayat. Khui and Seestani
on this would be the same as Ayats. Araki and Gulpaygani.
QUESTION(b)
Doesn't this type of behavior misguide people from the school of
Ahlul-Bayt? If it does, are we responsible for that?
ANSWER:
A(b) If it can be demonstrated to the jurists that it misguides
people, then perhaps they would prohibit it.
QUESTION(c)
What are the guidelines of Azaa that the Imams (as) have given
us? Have they instructed us to beat ourselves or have they condoned this?
ANSWER:
A(c) The Imams (a.s.) have given very general guidelines to us and
that is to mourn for them and show sorrow and grief. These different
rituals are human expression of public display of the grief. However,
Imam Husayn (a.s.) gave a clear instruction to his sister not to
scratch her face or tear apart her clothes.
Question:
My question is that, what is the actual wording of the ruling of Grand
Ayatullah Syed Ali Hussani Seestani (may he live long), on the issue of
"Zanjeer Ma'tam"?
Answer:
Ayatullah Seestani permits zanjeer matam provided there is no fear of loss of life or causing irreversible injury to any limb.