In the second of a series of articles looking at policing in Nigeria, the BBC's Andrew Walker meets a group of vigilantes who guard residential neighbourhoods in the south-eastern city of Enugu.
Paul Eze [r] goes out at night with a gun and a bell to protect his family
Paul Oparaji is the chairman of a local neighbourhood watch group in Enugu - quite normal for a pensioner, one might think.
But in Nigeria "neighbourhood watch" means taking to the streets with a gun or machete and possibly lynching armed robbers.
At an age where other men are keen to put their feet up and enjoy the company of their family, Mr Oparaji is a vigilante, prepared to dispense what he calls "jungle justice".
"Imagine myself, at 73 I haven't had a full night's sleep in eight years," he says.
"But if I don't do it, and robbers come here, my family and I will be maimed."
Every night at around 2230, he and 18 other men strap their ancient shotguns to their backs and walk through their neighbourhood banging a large metal bell to let the people in their houses know someone is watching over them, and let the robbers know someone is coming.
This "informal policing" happens in cities across Nigeria. The vigilantes are the only ones that stand between robbers and residents.
And if they get caught, a robber can expect to be killed before the authorities arrive.
The police say the presence of vigilante groups is "welcome".
"They pre-date the police, and they compliment our efforts. The police can't get into every nook and cranny," says police spokesman Emmanuel Ojukwu.
The police try to send officers out on patrol with as many vigilante groups as possible, but with one policeman for every 400 Nigerians this is difficult.
Any vigilantes who kill suspects would face the law, he said.
Until two years ago, the infamous Bakassi Boys policed the streets of neighbouring Anambra State.
They executed suspects with a "magic cutlass" which they said glowed in the presence of armed robbers - but only the Bakassi Boys themselves could see the glow.
Following a change in state administration, the Bakassi Boys were chased away, and other groups have taken their place.
The British government's Department for International Development (DfID) is working with vigilante squads like Mr Oparaji's, trying to educate them about the law and human rights to prevent them executing suspects.
They want to prevent groups like the Bakassi Boys from becoming popular again.
But on the streets of many Nigerian cities, people would rather police themselves and mete out their own punishment.
'Robbers deserve it'
"If you catch a thief you are expected to take him to the police, but we can give him jungle justice if he is armed," says Mr Oparaji, himself a retired policeman.
"If he is armed, if he wants to kill us, we don't feel sorry for him," he says.
Mr Oparaji is keen to say that he has never seen his vigilante group kill anyone, but he has heard of other groups catching and killing thieves.
"When I hear about that, I feel sorry because it means our people are not yet wise, but the robbers deserved it."
He appeals to the government to give vigilante groups like his guns.
"You cannot pursue the thief with an empty hand, or with a knife you cannot attack the thief with a gun."
The problem is that the police don't patrol many areas during the night.
"There is no-one who can protect us, they come and rob us and rape our children," said Paul Eze, 52, another vigilante group member.
"We aren't paid for this, it's a voluntary thing."
"Nigerian police only work in the afternoon, from midnight you can hardly see a policeman on the streets."
They accuse the police of hiring themselves out to rich people and businesses as armed security at night.
Vigilante groups are a well established part of Nigerian society.
People trust them more than they trust the police.
They are members of the community, and in the past robbers have been released by corrupt police officers and returned to torment the communities who handed them over.
Vigilante expert Chris Ugwu says many Nigerians see the rule of law as an alien concept.
"Some police have been compromised - the robber hands over some money and is released. He will go back and gloat to the people who handed him over."
"If they catch someone red-handed, they would much rather exact punishment on them then and there," he says.
Since 2006 the British government has been working with vigilante groups trying to educate them about the law and prevent them from lynching suspects.
It is part of the £30million Security Justice and Growth programme, which has been running in Nigeria since 2002.
They provide the groups with training and some equipment, like boots and rain coats.
They have registered vigilante groups and asked them to sign up to a charter requiring them not to execute suspects.
"There was a need to mobilise the public to compliment the efforts of the police," says Mr Ugwu, who works as a consultant for the British Council.
"But they were engaging in extra-judicial killing, torture, and there was the need to teach them about human rights."
He says it will be impossible to get rid of vigilante groups.
In the future he hopes they will have a different role, providing local intelligence for a more effective police force.
But Mr Oparaji says that in Nigeria people must be self-reliant.
"This is a country where wealth is flowing, but nobody protects anyone."
"If you can't protect yourself, you are finished," he says.