European embassies in Sudan on Monday jointly urged Khartoum to release all remaining political detainees held since protests against rising food prices erupted last month.
Their heads of mission also appealed to Khartoum to lift the state of emergency declared in two states in December.
On Sunday, the authorities released dozens of opposition activists and protesters held in a crackdown by security agents to prevent widespread anti-government protests after prices of food items, notably bread, surged in early January.
European embassies welcomed their release and called on Khartoum "to promptly release the remaining political detainees".
In a joint statement, the embassies said Khartoum should also "guarantee press freedom and freedom of assembly for peaceful demonstrations".
Hundreds of opposition activists, leaders and protesters were arrested after sporadic protests erupted in the capital and some other towns of Sudan following a surge in bread prices.
Many of the detainees were held in "inhumane conditions", according to a statement by Washington's mission in Khartoum issued last week.
Anti-riot police and security agents have so far swiftly managed to disperse the anti-government rallies.
Sudanese authorities are eager to prevent a repeat of deadly unrest that followed an earlier round of subsidy cuts in 2013.
Rights groups say dozens of people were killed when security forces crushed 2013 demonstrations, drawing international condemnation.
On Monday, the European embassies also urged Khartoum to lift the state of emergency declared on December 30 in the central state of North Kordofan and in the eastern state of Kassala that borders Eritrea.
A state of emergency is already in force in seven other conflict-ridden states, including the five states of war-ravaged Darfur in western Sudan.