At least seven people have been killed in three explosions as Nigeria celebrated the 50th anniversary of its independence.
Two car bombs detonated in the capital Abuja as the president was celebrating the anniversary. A third smaller explosion was also reported.
The explosions came after militants warned there was "nothing worth celebrating after 50 years of failure" in Africa's most populous nation, which is oil-rich but where most live on less than one dollar a day.
The attacks would be among the militants' boldest yet, striking in Nigeria's capital during an event with heavy security held hundreds of miles from the Niger Delta region where they are based.
A car bomb detonated just as a military formation began to march at Eagle Square, where President Goodluck Jonathan was on hand for the celebration.
Five minutes later, a second car bomb detonated, killing at least seven people, a police officer said.
At least one of the dead was a policeman, the officer added.
Inside Eagle Square, an AP reporter saw a small explosive detonate before members of the military gathered there. A security agent was seen lying on the ground near that blast.
The 50th independence anniversary ceremony continued without interruption, though attendees clearly recognised something had gone wrong.
The Movement for the Emancipation of the Niger Delta, the main militant group in Nigeria's oil-rich southern delta, had earlier issued a threat to journalists. "For 50 years, the people of the Niger Delta have had their land and resources stolen from them," the statement read. "The constitution before independence which offered resource control was mutilated by illegal military governments and this injustice is yet to be addressed."