Hundreds of protesters continued a sit-in near the headquarters of the military in the capital Khartoum for the second day on Sunday amid calls for Sudanese President Omar al-Bashir to step down.
Thousands of demonstrators staged mass rallies outside the headquarters on Saturday to demand the military intervene to force Bashir to resign.
At least four protesters were reportedly killed when security forces attempted to disperse the crowd, according to the Central Committee of the Sudanese Doctors.
Police, however, said only one protester was killed in clashes with security forces.
Police spokesman Hashim Ali said the demonstrator died in "riots" in the Sudanese capital on Saturday.
Sudan has been shaken by protests since last December, with demonstrators demanding the departure of al-Bashir, who has ruled Sudan since 1989.
