By Staff, Agencies  Four people have been shot dead at a demonstration in Omdurman, the twin city of Sudan's capital Khartoum, a doctor's committee said, as protest leaders and ruling generals resumed negotiations to finalise a power-sharing deal. The incident on Thursday occurred as thousands of demonstrators participated in a "million-man march" to protest the killing of four school children at a rally earlier this week in El-Obeid, the capital of North Kordofan in central Sudan.

Monday's rally, where two other demonstrators were also killed, was held to protest growing bread and fuel shortages.

“Four protesters have been killed by live ammunition and several wounded at a rally in Omdurman" on Thursday, the Central Committee for Sudan Doctors [CCSD], which is linked to Sudan's protest movement, said in a statement.

Earlier on Thursday, opposition leaders from the Forces of Freedom and Change [FFC] said they feared more violence against the protesters.

"We have credible information that militias of the old regime are planning to attack the protesters.

This will have serious consequences, and we urge the Transitional Military Council [TMC] to take its responsibility in protecting the protesters," said Abbas Madani Abbas, a leader of the protest movement.

"Otherwise, we will also hold them responsible in the killing of protesters," he added.

Protest leaders had called for the nationwide march on Thursday to "seek justice for the victims" and condemn the killings, which they blamed on the feared paramilitary Rapid Support Forces [RSF].

"Where is the investigation committee?" chanted protesters as they marched in the Burri and Bahri districts of the capital, sites of regular protests since unrest first erupted in December against the government of former President Omar al-Bashir.  A member of Sudan's ruling TMC said earlier on Thursday that seven members of the RSF have been arrested over the teenagers' killing on Monday