With visiting media kept firmly at arm's length, the trial opened on Monday of General Jean-Marie Michel Mokoko, a former presidential candidate accused by Congolese authorities of trying to stage a coup.Mokoko, 71 and a former chief of staff of the Republic of Congo's army, appeared in the criminal court to face accusations of "undermining internal state security" after a 2016 presidential poll in which he placed third.The general, once an advisor of long-serving President Denis Sassou Nguesso, faces a trial which his defence counsel says is "simply a settling of political scores."Reporters who had been able to enter the hearing were ushered out prior to the reading of the charge sheet.Other reporters, including journalists from French broadcaster RFI and AFP, were unable to access the building despite having accreditation.Only state television and official presidential media representatives were permitted to remain inside.Previous major cases have been open to the media, including a trial that followed blasts at an army arms dump in 2012 which killed almost 300 people.In March 2016, Mokoko won less than a 14% vote share as Sassou Nguesso was controversially declared a first-round winner. Sassou Nguesso, 74, has cumulatively spent almost 35 years in office since 1979.After the vote, Mokoko and other candidates called for a campaign of "civil disobedience."But "had he wanted to stage a coup he would have done so a long time ago. General Jean-Marie Michel Mokoko never said 'take up arms'," one of his lawyers, Norbert Tricaud, told RFI on Thursday.The charge sheet against him has to date not been made public.His Congolese and French lawyers say they will not speak at the trial.* Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.