The rallies, held in the capital Khartoum and its twin city of Omdurman, coincided with the International Day of the Disappeared.

At least 11 people were reported missing after the violent June 3 crackdown on a sit-in outside army headquarters in Khartoum, lawyers linked to the protest movement said earlier this month.

"We are calling for identifying the location of people missing since June 3," protester Moataz Mowaia Mohamed told AFP.

"We also want an independent investigation into their cases."

Protesters at one Khartoum rally carried pictures of the missing.

"I will remain steadfast, how can I go back (home) when I have someone missing," protesters chanted collectively.

Lawyer Shawki Yacoub told AFP that other protesters may also have gone missing since the crackdown, but said their cases would need further documentation.

Demonstrators launched the protest camp outside the army complex on April 6 as part of nationwide rallies calling for the overthrow of veteran leader Omar al-Bashir.

Days later, the generals ousted Bashir but the protesters kept up their sit-in to demand the new army rulers cede power to civilians.

At least 127 people were killed in the crackdown, according to medics linked to the protest movement.

Official figures put the day's death toll at 61.

This month Sudan embarked on a transition to civilian rule following a power-sharing deal signed between protest leaders and the generals.

On August 21, the country swore in a joint civilian-military ruling body and a prime minister as part of a roadmap to guide the country through a three-year transitional period.