It is 30 years since the end of one of post-independence Africa's first and most bloody wars.

The Nigerian civil war not only came close to tearing Africa's most populous country apart, it also provoked passions in many other parts of the world, particularly in Britain, the former colonial power.

Nigeria became independent in 1960. Like most ex-colonies in the continent, its boundaries had been defined quite arbitrarily to demarcate where the competing claims of the imperial powers collided.

Consequently Nigeria was composed of semi-autonomous Muslim feudal states in the desert north, and once-powerful Christian and animist kingdoms in the south and east, which was where the country's only significant source of income - oil - was exploited.

Ethnic split

At independence, Nigeria had a federal constitution comprising three regions defined by the principal ethnic groups in the country - the Hausa and Fulani in the north, Yoruba in the south-west, and Ibo in the south-east.

But as the military took over in the mid-1960s, and the economic situation worsened, ethnic tensions broke out.

Up to 30,000 Ibos were killed in fighting with Hausas, and around 1million refugees fled to their Ibo homeland in the east.

On 30 May, 1967, the head of the Eastern Region, Colonel Emeka Ojukwu, unilaterally declared the independent Republic of Biafra.

After initial military gains, the Biafran forces were pushed back.

Over two-and-a-half years later, 1 million civilians had died in fighting and from famine.

Photographs of starving children with huge distended stomachs from protein deficiency horrified people around the world.

Finally, Biafra was reabsorbed into Nigeria.

Responsibility

Today, Chief Emeka Ojukwu enjoys the role of elder statesman, living in comfort in the former Biafran capital, Enugu.

Forgiven by the Nigerian authorities in the early 1980s, he admits to no remorse for the events of the civil war.

"Responsibility for what went on - how can I feel responsible in a situation in which I put myself out and saved the people from genocide? No, I don't feel responsible at all. I did the best I could."

For the men who fought for the Biafran cause, defeat has been followed by 30 years of humiliation. The wounded veterans line up in their wheelchairs alongside the main roads in Enugu, begging for money from passers-by.

Men like former Sergeant Michael Okafo believe they are being punished for fighting on the losing side.

He wants food, he wants to educate his children and he wants shelter. He wants to be treated like any other Nigerian.

Exclusion

When the civil war ended, the government promised the Ibo people that there would be no victors and no vanquished.

The authorities were desperate to avoid a repetition of the ethnic tensions which preceded the war.

Chief Ojukwu believes the Ibos have been largely excluded from power ever since and this could cause instability in the future.

"None of the problems that led to the war have been solved yet," he says.

"They are still there. We have a situation creeping towards the type of situation that saw the beginning of the war."

British stance

There is plenty of resentment but little talk of secession among the Ibo today.

During the war, Mrs Oyibo Adinamadu was a leading women's activist for the Biafran cause.

But only a few African countries recognised it as an independent state.

She even travelled to Britain to lobby the then Labour government, which refused to meet her.

Instead Britain was a key arms supplier to the federal government, enabling it to crush the rebellion, because it believed that Biafran secession would create regional instability.

The then British Labour Foreign Secretary, Michael Stewart, agonised over this policy.

"It would have been quite easy for me to say: This is going to be difficult - let's cut off all connexion with the Nigerian Government," he says now.

"If I'd done that I should have known that I was encouraging in Africa the principle of tribal secession - with all the misery that could bring to Africa in the future."

Equitable

Today, Mrs Adinamadu thinks that equitable distribution of resources will encourage the Ibo of eastern Nigeria to believe in the future of the country.

"And if the easterners are treated fairly, and other parts of Nigeria too, and you see an equitable handling or distribution of what is available, and then of course working to develop and to progress - I think easterners would like to stay in Nigeria," she says.

But following Nigeria's recent return to democracy, many of the country's diverse peoples, not just the Ibos, are demanding greater autonomy.

Nigeria is a young country. The vast majority of its population is under 30 years old and only a small proportion have direct memories of the war.

But the causes of the Biafran conflict - ethnic rivalry and mistrust - are as relevant today as ever