The word 'carnival' summons up mental images of Venetian masked balls or scantily-clad samba dancers in Rio. But the carnival in the neighbouring villages of Ituren and Zubieta - in northern Spain's Basque country - is a much darker, scarier affair.

Every January, men from one village - wearing sheepskin costumes and bells on their backs - parade to the neighbouring town. According to tradition, the noise made by the bells ward off evil spirits. The bells also wake up the land so it can be ready to give prosperous harvest in spring. Villagers dress in bizarre costumes to scare visitors.

The carnival has seen a resurgence in popularity in recent years, though no one now can remember how or why this bizarre ritual began.

In this gallery, IBTimesUK presents photos from this year's event as well as some from previous celebrations.