A car bomb struck a religious procession in an area of north Yemen where Shiite rebels have been active, killing 15 people on Wednesday, a rebel spokesman told AFP.

"Fifteen people were killed and 30 others wounded in the car bombing that targeted a Shiite procession in Al-Jawf province," rebel spokesman Mohammed Abdulsalam told AFP by telephone.

Abdulsalam said the attack targeted Shiites who were preparing to mark Al-Ghadeer, the day on which Shiites commemorate the annointment of Ali, one of the key figures of their faith, as successor to the Prophet Mohammed.

The anniversary has long been a source of contention between the Sunni and Shiite branches of the faith.

The rebel spokesman did not rule out that the attack could have been a suicide bombing.