The Nigerian authorities have banned a procession by Muslims in the northern city of Kano, after appeals from Christian leaders.
Thousands of Christians fled last month's violence
The police outlawed Saturday's march by the Qadiriyya Sufi sect. It has been held annually for 59 years.
Dozens of Christians were killed in communal clashes last month in Kano.
The Christian Association of Nigeria said it had received information that the march would be hijacked by "agents of mass killing and destruction".
Religious tensions have been high in Nigeria since the massacre of hundreds of Muslims in the central Plateau State in May.
"The police have no choice but to ban the procession. This is to avoid hoodlums from hijacking it and causing more mayhem," Kano State police spokesman Mohammed Baba said.
"Many people are still displaced, and many wounds are yet to heal," he said.
Kano is predominantly Muslim but there is a small Christian community, who were targeted in last month's riots.
The annual procession is held to commemorate the founder of their order Abdulkadir Jilani, who lived in Iraq in the 11th century.
More than 10,000 people have been killed in ethnic, religious and political violence in the country since the end of military rule in 1999.
Nigeria's combined Christian and animist communities are roughly equal in size to its Muslim population, with the Christians living predominately in the south.