A previous toll given by the CCSD was 40 dead since the bloody dispersal on Monday of a weeks-long sit-in outside Army headquarters in Khartoum.
Videos showed billowing smoke and scenes of panic as the military tried to break up opposition sit-in in Khartoum.
The demonstrators demanded that the Transitional Military Council (TMC), which has ruled the country since troops ousted longtime President Omar al-Bashir in April, make way for a civilian-led interim body, CNN reported.
The committee said it held "the militias of the (military) council... responsible for this massacre".
Many of the injured were in a critical condition, according to the CCSD, which is close to the protesters.
Eyewitnesses said that the police and paramilitary Rapid Support Forces shot at protesters on Monday. Several videos showed security forces beating people with sticks. The Internet was blocked in places across the country by major providers.
Monday's attack drew international condemnation, including from UN Secretary-General Antonio Guterres. An attempt by the UK and Germany at the UN to call on the Sudanese military to stop the violence was blocked on Tuesday by China, which was backed by Russia.
Following the deadly crackdown, the military council announced it was abandoning all previous agreements reached with protest leaders on a transition to civilian rule.
Demonstrators had been occupying the square in front of the military headquarters since April 6, five days before Bashir was overthrown after 30 years in power.
( With inputs from IANS )