A Boko Haram suicide bomber has killed at least 21 people after blowing himself up among crowds at a Shia Muslim procession outside the city of Kano, Nigeria.
There is currently no indication of the number of casualties from the Islamic Movement of Nigeria march.
One of the organisers told the Agence France-Presse news agency: "It's a huge crowd so it's too early to give a precise figure of casualties.
"We now have the other suspect in custody."
The organiser, who wished to remain anonymous, told the agency the bomber ran into the crowd and detonated his explosives.
"He was dressed in black like everyone else. His accomplice was initially arrested and confessed they were sent by Boko Haram," he added.
He said the men were part of a group of young men abducted by Boko Haram last year.
The bomber detonated his explosives after realising his accomplice had been arrested, the organiser added.
Boko Haram, whose name translates to "Western education is forbidden" recently overtook Isis as the world's deadliest terror organisation.
The terror group has pledged allegiance to Isis.
