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.

zubieta bell carriers
Villagers wearing big bells on their backs, carrying horse tails on their hands and with rooster feathers on their colourful hats, march through Ituren's main squareReuters
shears
A costumed reveller carries rusted sheep shears during carnival celebrations in ZubietaReuters
mask tree
A man wearing a mask and rubber gloves takes part in carnival celebrations in ZubietaReuters
masks holes
Masked villagers look out from a carnival float during celebrations in the Navarran village of ZubietaReuters
dead body
A man wearing a mask and covered in animal entrails lies on a tree on the ground during carnival celebrations in ZubietaReuters
monkey mask
A man dressed as a demon walks through bonfire smoke during carnival celebrations in ZubietaReuters
sheepskin
"Joaldunak" (or bell carriers) parade to the neighbouring village of Ituren during a traditional carnival celebration in the northern Spanish region of NavarraReuters
masks chat
Young villagers wearing masks chat during carnival celebrations in ZubietaReuters
women f1
Villagers take part in carnival celebrations in Ituren, northern SpainReuters
wheelbarrow
Revellers attend a traditional carnival celebration in ZubietaReuters
xhainsaw
A man wearing a mask carries a chainsaw during carnival celebrations in ZubietaReuters
umbrella
People dressed in costumes walk along a street during carnival celebrations in ZubietaReuters
gun
Villagers wearing monster masks perform during carnival celebrations in ZubietaReuters
man and boy
A man and boy wearing costumes hold hands during carnival celebrations in ZubietaReuters
glasses
A villager wearing a carnival costume smiles during celebrations in Zubieta, northern SpainReuters
donkey mask
A villager wearing a monster mask walks with a donkey in the Navarran farming village of ZubietaReuters
devil fox
A reveller wearing a demonic mask lifts a fox into the air during carnival celebrations in ZubietaReuters