Khartoum: Sudan's military rulers offered to resume talks with opposition groups on Wednesday, two days after security forces mounted a deadly raid on a protest camp, but the opposition rejected the invitation.

Medics linked to the opposition said the death toll from Monday's operation and subsequent unrest had risen to 101 and that it was expected to increase further. They said that 40 dead bodies had been pulled out of the Nile. No official casualty figures have been released.

A protester stands in front of burning debris near Khartoum's army headquarters, in Khartoum, on Monday. Credit:AP

The raid, which followed weeks of wrangling between the ruling military council and opposition groups over who should lead Sudan's transition to democracy, marked the worst outbreak of violence since the army ousted President Omar al-Bashir in April after months of protests against his rule.

The Transitional Military Council cancelled all agreements it had reached with the opposition immediately after the raid but on Wednesday it rowed back amid mounting international criticism of the violence.