Clashes broke out in Warrap state when an argument erupted between the army and a young man.
According to statistics, about 60 million Nigerians between the ages of 18 and 40 are involved in active betting.
The two-day vote for 200 of the Senate's 300 seats will be largely contested by candidates backing Sisi.
Egypt and Sudan view the Grand Ethiopian Renaissance Dam (GERD) dam as a threat to vital water supplies.
Bashir, 76, and his co-accused could face the death penalty if convicted over the 1989 coup.