A Nigerian Shia group said police and security forces killed 12 of members and wounded 10 others during marches in the north of country to mark the religious commemoration of Ashura.
The Islamic Movement in Nigeria (IMN) Spokesman Ibrahim Musa said the Shia marchers were killed in the northern states of Kaduna, Bauchi, Gombe, Sokoto, and Katsina on Tuesday.
"The Islamic Movement in Nigeria has confirmed the killing of at least a dozen Ashura mourners across the nation during the peaceful Ashura mourning procession today," said Musa.
The group was banned in July after police crackdown on its rallies held to demand the release of its leader. IMN said the police were responsible for the deaths of at least 20 people in July but the police gave no death toll.
Police in the northern city of Kaduna, where IMN said three were killed and 10 injured on Tuesday, disputed the account and said it dispersed marchers "professionally".
A national police spokesman did not immediately respond to a request for comment, according to sources.
While roughly half of the nearly 200 million Nigerians are Muslim, mostly concentrated in the north of the country, Shia are a minority.