Political liberalisation ushered in by the return to civilian rule in 1999 has allowed militants from religious and ethnic groups to express their frustrations more freely, and with increasing violence.

Thousands of people have died over the past few years in communal rivalry. Separatist aspirations have been growing, prompting reminders of the bitter civil war over the breakaway Biafran republic in the late 1960s.

Politics: Parliament blocked moves to allow President Obasanjo to stand for third term in 2007. The army was the dominant political player until 1999

The imposition of Islamic law in several states has embedded divisions and caused thousands of Christians to flee. Inter-faith violence is said to be rooted in poverty, unemployment and the competition for land.

The government is striving to boost the economy, which experienced an oil boom in the 1970s and is once again benefiting from high prices on the world market. But progress has been undermined by corruption and mismanagement.

The former British colony is one of the world's largest oil producers, but the industry has produced unwanted side effects.

The trade in stolen oil has fuelled violence and corruption in the Niger delta - the home of the industry. Few Nigerians, including those in oil-producing areas, have benefited from the oil wealth.

Nigeria is keen to attract foreign investment but is hindered in this quest by security concerns as well as by a shaky infrastructure troubled by power cuts.

• Full name: The Federal Republic of Nigeria
• Population: 130.2 million (UN, 2005)
• Capital: Abuja
• Area: 923,768 sq km (356,669 sq miles)
• Major languages: English (official), Yoruba, Ibo, Hausa
• Major religions: Islam, Christianity, indigenous beliefs
• Life expectancy: 43 years (men), 43 years (women) (UN)
• Monetary unit: 1 Nigerian naira = 100 kobo
• Main exports: Petroleum, petroleum products, cocoa, rubber
• GNI per capita: US $560 (World Bank, 2006)
• Internet domain: .ng
• International dialling code: +234

President: Olusegun Obasanjo

Olusegun Obasanjo won a second term in April 2003, gaining more than 60% of the vote in Nigeria's first civilian-run presidential poll for 20 years. But opposition parties rejected the outcome, citing allegations of vote-rigging.

Nigeria's media scene is one of the most vibrant in Africa. State-run radio and TV services reach virtually all parts of the country and operate at a federal and regional level. All 36 states run their own radio stations, and most of them operate TV services.

The media regulator reported in 2005 that more than 280 radio and TV licences had been granted to private operators.

But TV stations in particular are dogged by high costs and scarce advertising revenues.

Radio is the key source of information for many Nigerians. Television viewing tends to be centred more in urban areas, and among the affluent. International radio broadcasters, including the BBC, are widely listened to.

There are more than 100 national and local newspapers and publications, some of them state-owned. They include well-respected dailies, popular tabloids and publications which champion the interests of ethnic groups. The lively private press is often critical of the government.

Media freedom improved under President Obasanjo. But restrictive decrees remain in force; in 2004 rebroadcasts of foreign radio stations were banned and concern was expressed over a proposed media law.

Citing high levels of violence, the media rights body Reporters Without Borders has said Nigerian journalists operate amid a "prevailing culture of brutality".