Thousands of demonstrators are spending a second night camped outside Sudan’s army headquarters, demanding that President Omar al-Bashir step down.
They appear to be hoping for an internal coup, pleading with the army command to remove Mr Bashir and open the way for a transitional government.
It is the biggest protest against Mr Bashir since the unrest began in December.
Mr Bashir has refused to leave, saying opponents should seek power through elections.
Security forces used tear gas and stun grenades to try to disperse protesters outside the army compound in the capital, Khartoum.
But eyewitnesses said soldiers intervened to protect activists, forcing the security forces to withdraw, and some civilians reportedly sheltered in the Sudanese navy’s headquarters.
