These pictures capture a gruesome blood sport that pits vicious dogs against wild boars in a fight to the death while baying Indonesian crowds look on. The snarling animals tear each other to pieces inside a bamboo arena in a remote part of Java island.

The hundreds of villagers packed into the stands appear to relish the contest between specially bred fighting dogs and captured boars. The fights are known locally as "adu bagong".

The tradition began in the 1960s when the wild pig population shot up and threatened to destroy the crop yield. Farmers hunted and killed them before a prize fighting culture evolved.

Participants told Reuters the fights were a way to preserve a tradition of hunting in the area. "It used to be very simple, not like now when the dogs are trained. From there it's been handed down and has even become part of tradition and culture," said Nur Hadi, head of a local hunting group.

Breeders can earn up to $2,000 (£1,500) if their dogs come out on top against the beasts, which are feared around the world and have even been reported to kill Isis jihadis.

Locals say the boars test the agility and hunting skills of the fierce canines. A variety of different breeds are thrown into the 15m by 30m ring, which has a water pit at one end.

If a boar is lucky enough to survive a fight, it is healed and then returned to the arena to fight on another day. When it eventually dies, it is butchered and sold for meat.

Unsurprisingly, animal rights groups are critical of the sport. Indonesian activist Marison Guciano said: "It is a criminal act against animals."

"The government and NGOs should go to the field to stop this event and educate the people that dog fighting is not right."

Dog breeder Agus Badud defended the practice, argunig that it gave local people a means of earning money.

He said: "I take part in this contest to increase the selling price and economic value of my dogs, and it would be useless for me as a breeder if I did not participate in a contest like this," Badud said in his house where he keeps 40 dogs.

Dog Wild Boar fighting Indonesia
A dog is flipped by a wild boar fight during a fight in Indonesia Reuters/Beawiharta Beawiharta
Dog Wild Boar fighting Indonesia
The crowd at a dog and wild boar fight, known locally as 'adu bagong' in Indonesia Reuters/Beawiharta Beawiharta
Dog Wild Boar fighting Indonesia
There is a water pit at one end of the bamboo arena Reuters/Beawiharta Beawiharta
Dog Wild Boar fighting Indonesia
One of the fighters is mobbed by children outside the arena Reuters/Beawiharta Beawiharta