At least 11 people were wounded by gunfire near a protest sit-in in the Sudanese capital Khartoum on Saturday, Reuters reported an opposition doctors' committee as saying.
Sudan's main protest group blamed the violence on the Transitional Military Council (TMC), saying that it is part of a plan to violently clear the protests.
"The killing and intimidation on Nile Street is just a prelude to committing a massacre to end the sit-in by force," Sudanese Professionals' Association (SPA) said in a statement late on Saturday.
Tensions are mounting between the TMC and an alliance of protest and opposition groups who want a quick handover of power to civilians.
TMC officials could not immediately be reached for a comment.
The head of the central Khartoum military region said on Thursday the protest site "has become unsafe and represents a danger to the revolution and the revolutionaries and threatens the coherence of the state and its national security."