A Nigerian secessionist group has condemned the authorities for charging 53 of its members with treason for playing in a youth football tournament.
Massob revives memories of the horrors of the Biafran civil war
It was organised by the banned group Massob, which is campaigning for a separate eastern state of Biafra.
Biafran sessetionist calls led to a three-year war in the 1960s in which more than one million people died.
"The government is intimidating people. It is not treason," Massob's legal advisor Uche Okwukwu told the BBC.
According to the BBC's Sola Odunfa, the treason charge on Tuesday came as a surprise after the men had spent six months in custody.
The charge sheet stated that by appearing in September championship in Nigeria's biggest city, Lagos, the men "had levied war on Nigeria".
Massob - Movement for the Actualisation of a Sovereign State of Biafra - was banned three years ago. It says it is pursuing its objectives for the Ibo people in eastern Nigerian peacefully.
Mr Okwukwu said it was now illegal for anyone to wear T-shirts, caps or stickers supporting Biafra's independence.
"Even if they see you with a Biafran flag they charge for treason," he told the BBC's Focus on Africa programme.
Several Massob members have died in the last three years in clashes with the police in south-eastern Nigeria, where it draws the bulk of its support.
The government is intolerant of its existence because it revives memories of the horrors of the civil war against Biafra in 1967, our correspondent says.
The case was adjourned on Tuesday until next week.