Ali Kushayb, a senior member of the Janjaweed, was severely wounded in his hands in the assassination attempt by a gunman, the Sudan Times reported Sunday.
The bodyguard was not identified.
The alleged assailant was arrested.
Adam Mahmoud Jar al-Nabi, the governor of South Sudan state where the attack occurred, identified Kushayb as an "assistant at the Central Reserves police."
A witness said Kushayb was inside a car-repair shop in Nyala at the time of the Saturday attack. Merchants and customers fled a nearby market in fear of retaliative attacks by Janjaweed members.
The International Criminal Court issued an arrest warrant for Kushayb for alleged war crimes and crimes against humanity in Darfur, the western region of Sudan.
Kushayb participated in recent deadly attacks on civilians in central Darfur, Human Rights Watch reported.
Local officials imposed a 7:30 p.m. to 7 a.m. curfew in South Sudan last week after five people died in clashes between security forces and a tribal militia.