Nigerian forces opened fire on Wednesday at Shia mourners in Ashura processions, killing more than nine people in the cities of Kaduna and Funtua.
The killings came as Shia mourners defied a state ban and held Ashura processions in several cities to mark the anniversary of Imam Hussein's martyrdom, the third Shia Imam, Press TV reported.
There have been conflicts between the Nigerian regime and the country's Shia Muslims who demand the release of prominent Shia cleric Sheikh Ibrahim Zakzaki from jail.
Scores of Nigerian forces surrounded a mourning ceremony in Kaduna as an ambulance waited nearby, UK-based Islamic Human Rights Commission (IHRC) reported.
According to a local newspaper, the incident occurred at the residence of senior Shia leader Muhtar Sahabi.
It also said that armed trips and mobile police officers gathered around the compound and were waiting for those who had gathered inside to leave.
Press TV correspondent from the capital Abuja reported that troops fired tear gas and live bullets at mourners in Funtua and Kaduna.
The conflicts came after a series of arrests during recent days of members of the Islamic Movement in Nigeria (IMN) which is the mainstream Shia group led by Sheikh Zakzaky.
The Nigerian regime has imposed a ban preventing the movement's supporters from taking part in ceremonies marking the month of Muharram during which Imam Hussein and his 72 companions were martyred nearly 14 centuries ago.