The terrified victim rears up on his hind legs and veers away in a desperate bid to escape, but it is no use.

"These tournaments are truly barbaric," says Andrew Plumbly of the welfare group Network for Animals, which has been campaigning to bring an end to the savage contests.

These scenes in the town of Don Carlos involved 54 horses, many of which had gruesome injuries

"Our vets have seen horses being kicked in the head so hard that their eyes have popped out of their sockets. Other horses have had their ears ripped off. It's straight out of the Middle Ages."

Horse-fighting occurs almost exclusively in Mindanao in the southern Philippines, and in parts of China.

Though horses do not normally fight one another, these stallions had been whipped into a fighting frenzy by the presence of a young mare who was "in season" and had been staked to the ground in the middle of the muddy arena.