Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
Dear brother, thank you for your question that shows your interest in Islamic knowledge.
Indeed, Islam does not advocate such deeds at all; many countries worldwide received and accepted Islam but none of such actions were approved or done in the Islamic history.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and an Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
I think you are guilty of a making a false allegation against the Shiie Muslims. I don’t know of any Shiite scholar advocating this. Perhaps some of the Salafites may be advocating such a move.
Anyhow, Islam does not sanction any such actions. There were many historical monuments of previous nations in the countries that received Islam. However, there was no official policy endorsed by the Caliphs at the advice of Muslim scholars to destroy such sites or monuments.
Allah Almighty knows best.