Shocking pictures have revealed a glimpse into the mostly hidden world of a brutal Nigerian sport known as Dambe.
The sport is like boxing but without protection. Opponents choose their strongest hand and wrap it in hard rope.
Their other hand is meant to act as a shield. Until recently, competitors were allowed to dip the hard rope in resin and even coat it in shards of glass.
That practise is now illegal but the sport is still deadly. And knocking your opponent out is even known as 'killing' them.
The ancient tradition is usually practised by Hausas in the north of Nigeria but it has spread to southern areas as well.
Dambe fighters in Lagos battle on the beach under floodlights while jumbo screens replay them for audience members who are far away.
The way to win the fight, which is centuries old, is by punching and kicking your opponent until they fall down.
The tradition is entrenched among butcher caste groups and is very heavily focussed on communities.The sport started from clans of butchers travelling to different villages at harvest and fighting those from the area as part of the festival entertainment.
Butchers come from a lower caste of Hausa society - they are the only ones who could ritually slaughter animals and handle meat. They would form teams from the village - known as armies - and challenge men from other butchers guilds, as well locals from the audience.
Nowadays, that sense of team is still very strong, and the sport is still dominated by the butchers caste, but competitors will often be very young - teenagers who train in gyms and yards - and will fight all year round.
Fighters join a professional community which travel to fight, often now in temporary rings, rather than just inside a circle of spectators as in the past. They fight for prize money - just as they did traditionally - as harvest was a time of wealth.
An average competitor will win 200,000 naira ($556) in a fight and some make careers out of it.
They wear shorts, rather than loincloths, and the pre-fight entertainment is more elaborate, and can even use sound systems.
Fights last three rounds - though these rounds are not timed - their end is signified either when there is a lull in the action, one of the contestants or an official calls a stop to it, or when someone is knocked down.
There are no official weight classes, though fighters are normally matched up with someone of a similar size.
The strapped up strong arm is knows as the 'spear', while the front hand is called the 'shield' - and must be held with the palm open and facing the opponent. As well as for protection, the shield can also be used to grab hold of an opponent.
Contestants can also kick with both legs - the lead leg can sometimes be wrapped with a chain and is also used for defence.
Some fighters cut their legs and arms with razor blades before putting 'medicine' in them and wrapping them in hard rope.
Other traditions include the use of amulets for supernatural protection, with some fighters wrapping them to their spear hand, while some of the fighting groups also ritually smoke marijuana before matches.