A Federal High Court has ordered Nigeria's secret police to immediately release the leader of a separatist Biafra group — a cause that led to a civil war that killed a million people in the 1960s.

Lawyer Vincent Obeta told The Associated Press that the State Security Service had not complied with the order by late Thursday. The prosecution argued for more time to prepare for trial and that a man facing charges of terrorism and financing terrorism is a flight risk.

Nnamdi Kanu was arrested Oct. 17 trying to board a plane to London.

His detention has sparked protests in southeastern Nigeria, where some Igbo people want to create a new country. At least 10 people including two police officers have died in demonstrations that turned violent.