Hundreds of Shiite Muslims marched through Nigeria's northern city of Kano to mark both the birth of the Prophet Muhammad and the killing of hundreds of Shiites by Nigerian soldiers nearly two weeks ago.

Human rights activists say Nigerian troops killed many hundreds of Shiites in raids in the northern town of Zaria over three days Dec. 12 to Dec. 14. The army says it acted after Shiites tried to block the convoy of Nigeria's army chief — a charge the Shiites deny.

The government said it is investigating the incident.

Thursday's procession was led by Abdulhamid Bello, who said justice must be served. He read a statement saying the marchers mourn the killings and the detention of their leader, Ibraheem Zakzaky, who started Nigeria's Shiite movement 37 years ago.