Sudanese authorities released on Friday two anti-coup figures from the Communist Party a day after their arrest, the party said.
The military's October takeover in Sudan has sparked nationwide demonstrations which sparked a crackdown that has killed at least 95 protesters and wounded hundreds, medics say.
Hundreds have also been arrested after rallies calling for civilian rule in the northeast African nation.
On Thursday during protests mainly in the capital Khartoum, authorities arrested the Communist Party's political secretary Mohammed Mukhtar al-Khatib and another member.
They were detained after meeting rebel leader Abdel Wahid Nour who has refused to sign a landmark 2020 peace deal with the Sudanese government, the party said.
The pair were released on Friday, it said.
Army chief Abdel Fattah al-Burhan, who led the coup, pledged in April to release political detainees to set the state for talks among Sudanese factions.
Last year's military power grab has sparked international condemnation.
The United Nations and African Union have called for a dialogue between all Sudanese factions to resolve the crisis.