South Korean President Yoon Suk Yeol is in court for a hearing where his lawyers are contesting his arrest on a criminal charge alleging he was orchestrating a rebellion when he imposed martial law.

With Yoon in attendance as hearings opened Thursday, the courtroom was packed and there was heavy security around the building. The 64-year-old former prosecutor has been behind bars since he was arrested last month on charges of insurrection,

South Korean police are formally building a case against impeached President Yoon Suk Yeol over accusations he obstructed the execution of an arrest warrant, a police spokesperson said on Friday. A South Korean court issued an arrest warrant for Yoon on December 31 in a criminal investigation accusing the suspended leader of insurrection over his martial law decree last year.