Bashir arrived at court in Khartoum wearing a white shirt, face mask and plastic gloves, surrounded by security officials.
He stands trial alongside more than 20 former officials including Vice President Ali Osman Taha and Ali al-Haj, secretary general of the Islamist Popular Congress Party (PCP), Reuters news agency reported, citing judicial officials.
The ousted Sudanese leader already received a two-year sentence in December over corruption charges, and had his money confiscated, according to the Suna state news agency.
He faces further charges over the killing of demonstrators, and is also wanted by the International Criminal Court on charges of genocide, war crimes and crimes against humanity allegedly committed in Darfur. The government has not ruled out sending Bashir to The Hague, or having him tried by the ICC in Sudan.
Hundreds of people turned up at the court hearing on Tuesday, according to Reuters. Lawyers, supporters, family members and journalists all complained that they could not get access to the hearing.
“We decided to postpone the trial session to 11 August as we need a bigger hall in order to guarantee social distancing, put different arrangements in place and ensure that the entire defendants have lawyers and other rights,” the judge said, reported Anadolu news agency.
1989 coup
Bashir seized power in 1989 when he led fellow officers in overthrowing Prime Minister Sadiq al-Mahdi and his democratically elected government, saying the coup was to “save the country from rotten political parties”.
He made himself chairman of the Revolutionary Command Council and then dissolved government, and other institutions, as well as political parties and trade unions. Demonstrations were banned and a state of emergency was imposed.
Later in April 1990, 31 members of the security forces were executed following an alleged coup plot, however, some believed claims of a coup were a cover for removing suspect officers.
Lawyers for Bashir said in December that the trial was a political charade since it was more than 30 years after the event.
It will be hard for most of the defendants to deny their role in the 1989 coup, according to Wasil Ali, former deputy editor of Sudan Tribune. It is not clear whether a statute of limitations applies and if they can be tried using a penal code that was subsequently scrapped.
While it will be very hard if not impossible for most defendants to deny participation in the 1989 coup (flatly illegal under the laws at the time & possibly punishable by death) it remains to be seen if they can be tried using a penal code that was scrapped post-coup & whether..
— Wasil Ali - واصل علي (@wasilalitaha) July 16, 2020
Bashir was overthrown following mass protests and the intervention of the military. A civilian authority took over from Bashir through a three-year power sharing agreement with the army.