CAIRO—Egypt’s highest civilian court on Monday upheld death sentences for 12 senior Muslim Brotherhood figures over a 2013 sit-in which ended with security forces killing hundreds of protesters, judicial sources said. The ruling, which cannot be appealed, means the 12 men could face execution pending approval by President Abdel Fattah al-Sisi. They include Abdul Rahman Al-Bar, commonly described as the group’s mufti or top religious scholar, Mohamed El-Beltagi, a former member of parliament, and Osama Yassin, a former minister. Many Muslim Brotherhood figures have been sentenced to death in other cases related to the unrest that followed the military’s ousting of Brotherhood president Mohamed Mursi in 2013, but the Court of Cassation ordered retrials. Monday’s ruling relates to a mass trial of hundreds of suspects accused of murder and incitement of violence during pro-Brotherhood protests at Rabaa al-Adawiya square in Cairo in the weeks after Mursi’s overthrow. In September 2018, …