Nigeria's most prominent militant group warned in a statement on Friday that explosive devices had been placed at the venue of celebrations marking 50 years of independence for the country.
"With due respect to all invited guests, dignitaries and attendees of the 50th independence anniversary of Nigeria being held today ... the Movement for the Emancipation of the Niger Delta (MEND) is asking everyone to begin immediate evacuation of the entire area within the next 30 minutes," it said.
"This warning expires after 10:30 Hrs (0930 GMT). Several explosive devices have been successfully planted in and around the venue by our operatives working inside the government security services. In evacuating the area, keep a safe distance from vehicles and trash bins."
The deadline arrived without any apparent incidents. The venue of independence celebrations in the capital Abuja, where foreign delegations and Nigerian leaders were located, was not evacuated.
MEND has staged scores of attacks in the oil-rich Niger Delta in recent years, claiming to be fighting for a fairer distribution of oil revenue.
However, thousands of oil militants signed up to a government amnesty programme last year and unrest in the region has been greatly reduced.
"There is nothing worth celebrating after 50 years of failure," MEND said in Friday's statement.
"For 50 years, the people of the Niger Delta have had their land and resources stolen from them."