A Nigerian judge on Wednesday adjourned the trial of separatist leader Nnamdi Kanu until January after his lead lawyer walked out in protest because security agents refused other defence lawyers access to the courtroom.

At his last court appearance on Oct. 21, Kanu, a British citizen, pleaded not guilty to seven charges that included terrorism, calling for secession and knowingly broadcasting falsehoods.

Kanu’s case underlines the government’s concern over growing discontent and insecurity in Africa’s most populous country.

Ifeanyi Ejiofor, Kanu’s lead lawyer, had planned to challenge the competence of the charges on Wednesday. But state security agents barred Kanu’s other lawyers, including a U.S.-based attorney, from entering the courtroom.

In a court recording obtained by Reuters, the judge is heard asking whether Kanu wanted the trial to proceed without his lawyers, to which he said “no, my Lord.”

Kanu then complained that he had not been allowed to see his U.S.-based lawyer: “I have not been allowed to see him. He is here to see me and to observe the proceedings.”

Wednesday’s proceedings lasted 20 minutes and the trial was postponed to Jan. 19 and 20 next year.

Security agents again barred journalists from entering the court.

The military considers Kanu’s Indigenous People of Biafra (IPOB) a terrorist organization, which the group denies.

IPOB wants a swathe of the southeast, homeland of the Igbo ethnic group, to split from Nigeria. An attempt to secede in 1967 as the Republic of Biafra triggered a three-year civil war that killed more than 1 million people.

Kanu was first arrested in 2015, but disappeared while on bail in April 2017. His social media posts during his absence outraged the government, which said his comments sparked attacks on security forces in southeastern Nigeria.

Security agents produced him in court in Abuja on June 29 after detaining him in an undisclosed country. His lawyer alleged he was detained and mistreated in Kenya, though Kenya has denied involvement.