Sudanese security forces have closed major roads and bridges in the capital, Khartoum, as anti-government activists plan mass protests on the first anniversary of the latest military coup.
More than 100 people have been killed in violent protests since October last year.
The junta has been under pressure from the international community.
On Monday the US said it could sanction those undermining the transition to civilian rule.
Despite expressing a commitment to democratic reforms, Sudan’s military rulers have gradually tightened their hold on power and reneged on political and social changes pledged after the removal of long-serving leader Omar al-Bashir in 2019.