A doctor and a child were killed after protesters tried to march on the presidential palace in Khartoum on Thursday, a doctors’ committee linked to the opposition said.
The victims were identified as Babiker Abdelhameed and Mohamed Ebeid.
The group, which is part of protest organisers, said in a statement that several protesters were also wounded during anti-government demonstrations in the capital.
Sudanese police had fired tear gas and live bullets at demonstrators, witnesses said, during the protests in Khartoum to demand that President Omar al-Bashir step down immediately.
Protests erupted in several cities in Sudan on Thursday.
Police authorities could not immediately be reached for comment.
Protests that broke out on December 19, after the government raised the price of bread, have turned into nationwide demonstrations against Bashir's three decades of rule.