Violence broke out when police tried to disperse thousands of members of the Islamic Movement in Nigeria (IMN) who were marching from Kano to Kaduna for the Ashura religious festival.
“The police arrived and started firing teargas canisters on the procession of Shiites to disperse them,” grocer Ilyasu Ammani told AFP.
“I saw 15 bodies sprawled on the ground before the police evacuated them,” said Ammani of the violence in Kwanar Dawaki, an area on the outskirts of Kano.
Witness Kabiru Mudassir said he saw more than “10 bodies being taken away in a police van.”
Mudassir, who was on his way to work when he was caught in the fighting, said “more policemen are being deployed and a military jet keeps circling the area.”
Nigerian police said they opened fire on the crowd after one of their officers was hurt.
“They injured one of our officers and our men opened fire because they were becoming violent,” said a police officer who asked to remain anonymous.
The violence comes just over a month since 10 IMN members — who were also in the streets for religious celebrations — were killed in the town of Funtua in northern Katsina state following clashes with security forces.
In October, Kano police banned IMN from conducting street processions ahead of the annual Ashura rites.
Kaduna state governor Nasir El-Rufai banned the group as an “unlawful society”, saying it was a security threat and calling for security forces to “vigorously” arrest its members.
The IMN seeks to establish an Islamic state through an Iranian-style revolution and has been in conflict with the Nigerian government over the years.
In December last year the group fought against soldiers for two days in the city of Zaria.
The fighting left over 300 IMN members dead while leader Ibrahim Zakzaky was left partially paralysed and blind in one eye.
Experts warn that the heavy-handed Nigerian response to the sectarian issue is stoking tension at a time when security forces are already overstretched fighting Boko Haram jihadists in the northeast and Niger delta militants in the south.