In a post on his Twitter account on Monday, Sadr called for helping those in need, raising flags of mourning and covering public and private places in black, increasing acts of worship and reciting the Quran, and visiting pilgrimage sites while observing the health protocols.
He also called for easing sectarian and political tensions and moving toward unity.
Shia Muslims around the world mourn the martyrdom of Imam Hussein (AS), the Sayyid-ul-Shuhada (master of martyrs), in Muharram, the first month in the lunar Hijri calendar.
The third Shia Imam (AS) and a small group of his followers and family members were martyred by the tyrant of his time - Yazid Bin Moaweya, in the battle of Karbala on the tenth day of Muharram (known as Ashura) in the year 680 AD.
The coronavirus outbreak that originated in Wuhan, China, has infected over 20 million people around the world and killed over 734,000.
The outbreak has had a major impact on global sporting, cultural, religious and political events, with a host of events canceled or postponed.