The Nigerian police have fired tear gas to disperse protesters who had gathered in the capital, Abuja, over the continued detention of separatist leader Nnamdi Kanu.

The protesters, led by activist and publisher of the Sahara Reporters news site, Omoyele Sowore, want the immediate release of Kanu, who is on trial on terrorism charges and heads the outlawed Indigenous People of Biafra (Ipob).

Kanu, who has been in detention since 2021, has denied the charges. He also holds British nationality.

Ipob is seeking independence for what they call the Biafran nation in south-eastern Nigeria.

Eyewitnesses said police officers fired multiple rounds of tear gas at people who had begun to gather as early as 07:00 (06:00 GMT).

The police also blocked major roads in the capital, causing heavy gridlock and confusion across several parts of the city.

Sowore wrote on X that security operatives had arrested several individuals, including Kanu’s family members and legal team.

The police have not commented on the reported arrests.

Despite his many battles with the Nigerian government, Kanu remains a cult hero to his many followers, especially in south-east Nigeria.

Ipob was banned as a terrorist organisation in 2017. Its armed wing – the Eastern Security Network – has been accused of killings and other acts of violence in recent years.

Kanu was first arrested in October 2015 on terrorism charges but he jumped bail in 2017 and left the country after a military raid on his home. The court later revoked his bail in March 2019 and ordered his re-arrest.

Two years later, the Nigerian government announced his re-arrest. His lawyers say he was detained in Kenya, which has not commented on whether it played a role in his deportation to Nigeria.

In 2022, an appeal court ordered that the charges against him be dropped but this was overturned by the Supreme Court the following year.

His legal team is due to start his defence on Thursday after the court threw out their argument that he had no case to answer.