Sudan votes on re-electing indicted President Bashir
But voters were left with few alternatives after Mr Bashir's main challengers boycotted the race, citing widespread fraud before the voting even began.
The elections, which run through Tuesday, are supposed to be an essential step in a 2005 peace plan that ended two decades of a civil war between the north and south, a conflict that claimed some 2 million lives.
The vote was meant to kick-start a transformation to a democratically elected government that would prepare the ground for a crucial referendum next year on whether southern Sudan forms an independent nation.
There were also hopes that the first multi-party elections in nearly a quarter century would begin a process of healing in the impoverished country ripped apart by the north-south civil war and the seven-year conflict in the western region of Darfur, which left an estimated 300,000 dead and millions displaced since 2003.