ABUJA, Nigeria (AP) -- Two car bombs exploded Friday as Nigeria celebrated its 50th independence anniversary, killing at least eight people in an unprecedented attack on the nation's capital by militants from the oil-rich southern delta region.
The attacks claimed by the Movement for the Emancipation of the Niger Delta came as the President Goodluck Jonathan and other dignitaries sat only a 10-minute walk away.
The bombings raise new questions about political stability and security in Africa's most populous nation as it approaches a critical presidential election and remains one of the world's top crude oil suppliers.
The militant group issued a warning to journalists about an hour before the attacks, telling people to stay away from festivities at Eagle Square in the nation's capital of Abuja. It blamed Nigeria's government for doing nothing to end the unceasing poverty in the delta as the nation receives billions of dollars from oil revenue.
"There is nothing worth celebrating after 50 years of failure," the group's statement read. "For 50 years, the people of the Niger Delta have had their land and resources stolen from them."
The group said the explosive devices had been planted by "operatives working inside the government security services."
Police Minister Adamu Waziri said that eight people had been killed and 18 others wounded in the attacks.
The car bombings seemed designed to lure first-responders and then kill them with a second blast. Five minutes after the first vehicle exploded, the second went off, a police officer told an Associated Press reporter at the scene. At least one of the dead was a policeman, the officer said. The officer spoke on the condition of anonymity because he was not authorized to speak to reporters.
A Nigerian Red Cross spokesman said his group transported 38 wounded people to local hospitals, where doctors desperately needed blood for transfusions.
Inside Eagle Square, an AP reporter heard a small explosion before members of the military paraded in front of the gathered dignitaries. A security agent was seen lying on the ground afterward, though the militant group later denied placing any explosives inside the venue.
The anniversary ceremony continued without interruption. Afterward, Jonathan's office issued a statement condemning the "wicked and dastardly" attack.
"The president wants these families to know that their loved ones have not died in vain," the statement read. "Rather they have paid the supreme price for our unity; and in their death, they have watered the tree of our freedom."
It added: "To those behind these vicious acts, the president wants you to know that you will be found, and you will pay dearly for this heinous crime."
The militant group later acknowledged that it knew allowing the second car bomb to detonate would put passers-by at risk. However, it faulted Nigerian officials for ignoring the warning before the bomb blasts.
"The blame goes to the Nigerian authorities and our message to the families of those who may have been affected is that we deeply regret any loss of life," a statement issued Friday afternoon to the AP read.
The Movement for the Emancipation of the Niger Delta has destroyed oil pipelines, kidnapped petroleum company workers and fought government troops since 2006. Violence in the delta drastically subsided after a government-sponsored amnesty deal last year provided cash for fighters and the promise of job training. However, many ex-fighters now complain that the government has failed to fulfill its promises.
The militant group appeared to splinter over the amnesty program, though it proved its operational abilities in March when it detonated two car bombs near a government building in the Niger Delta where officials were discussing the deal. The blasts wounded two people in an attack heard live on television. The group also used car bombs in several attacks in 2006 that killed at least two people.
Friday's attacks come a day after the group said security agencies in South Africa raided the home of its former leader Henry Okah. Okah was freed from a Nigerian jail in July 2009 after the nation's attorney general dropped the treason and gun running charges against him. He later moved to Johannesburg.
The militant group said investigators raided Okah's house after the Nigerian government "sent a false petition claiming Okah planned to overthrow the government and other claims." Police in South Africa could not confirm any raid took place at Okah's home.
Nigeria, a member of OPEC, is one of the top crude oil suppliers to the U.S. Over recent years, attacks by militants led to a sharp drop in oil production. However, as an uneasy peace has taken hold in the delta, Nigeria boosted its oil production and is vying with Angola to reclaim its spot as Africa's No. 1 exporter.
Home to 150 million people, Nigeria won its independence from Britain in 1960. Coups and military dictatorships plagued the nation for decades until democracy took hold in 1999. Next year, it faces a crucial presidential election as a number of candidates plan to challenge Jonathan, who reached the nation's highest office after the death of its elected leader Umaru Yar'Adua.
Corruption slinks into every level of society in the country, leading many to worry about vote-rigging. However, Jonathan offered an optimistic assessment during a televised speech Friday morning, telling the country "the worst is over" and promising a free and fair election.
But Jonathan - and the rest of the nation - faces an increasing threat from a radical Muslim sect in the country's north that engineered a prison break last month. That's on top of the possibility of a renewed militancy heading back into the delta's creeks as oil production appears to be on the rise, buoyed by its unprecedented assault on the symbol of Nigeria's political power.
"This can't be ignored," said Mark Schroeder, the director of sub-Saharan Africa analysis for the U.S. security think tank STRATFOR. "Now it's smack-dab in the middle of the national celebrations. You can't sweep that under the carpet."
Gambrell reported from Lagos, Nigeria. Associated Press writers Lekan Oyekanmi in Abuja, Nigeria and Donna Bryson in Johannesburg contributed to this report.