Thousands took to the streets in Khartoum and other cities to commemorate the 128 people who medics say were killed when armed men in military fatigues violently dispersed a months-long sit-in outside army headquarters.
The latest demonstrations came as UN human rights expert Adama Dieng visited Sudan and urged authorities to "refrain from use of excessive force".
The protests in 2019 were crucial to pressing the military into sharing power with civilians in the wake of the ouster in April that year of longtime president Omar al-Bashir.
But a military coup led by army chief Abdel Fattah al-Burhan in October last year derailed that fragile political transition, and protesters have returned to the streets at least weekly since then -- often in the face of renewed deadly force.
The police released a statement accusing demonstrators of attacking police stations, wounding policemen and causing damage.
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