Nigerian treason trial to start
The treason trial of Nigerian oil militant Mujahid Dokubo-Asari is due to start shortly at the Federal high Court in the capital, Abuja.
He was arrested in 2005 after calling for the oil-producing Niger Delta to secede from the rest of Nigeria.
A BBC correspondent says the government is under pressure to release Mr Dokubo - a key demand of those who have staged a wave of attacks on oil facilities.
Last year, Nigeria lost some $4bn because of unrest in the Niger Delta.
Mr Dobubo's lawyers are expected to ask for his release on bail.
The BBC"s Senan Murray says there is tight security outside court, with a truckload of riot police on standby in case of any trouble.
But he says there are no demonstrators.
Last week, Nigeria's Army Chief of Staff Major General Andrew Azazi, who is from the Delta, met some oil militants, who repeated their demand for Mr Dokubo's release if the violence is to stop.
They also want former Bayelsa State governor Diepreye Alamieyeseigha to be freed - he is accused of corruption and money laundering.
The militants often attack oil installations and kidnap oil workers for ransom.
Last year, such attacks cut Nigeria's oil output by some 20 percent.
Nigeria is Africa's biggest oil producer but most of the Niger Delta population remain poor.
The militants say more of Nigeria's oil wealth should benefit local people.