A Libyan newspaper says about 50,000 people were killed during the six-month period before the rebels took over the capital Tripoli.
Hisham Abu Hajar, co-ordinator of the opposition fighters in Tripoli, said the death toll included rebels and civilians killed since the uprising began in February, the Benghazi-based Quryna newspaper reports.
Mr Hajar said they depended on statistics by the Red Cross and included deaths from battles in Tripoli, Misrata and the western mountains against forces loyal to Muammar Gaddafi, the report on Wednesday said.
Rebels are still trying to re-establish security and meet locals' needs for basic items and services in the capital, a week after they declared control of Tripoli, the DPA news agency reports.
The Transitional National Council has given gave forces loyal to Colonel Gaddafi until Saturday to surrender, hoping rebels would enter his stronghold of Sirte and southern areas peacefully to "avoid more bloodshed and destruction".
Sirte, Colonel Gaddafi's hometown, is on the Mediterranean coast between Tripoli and the eastern city of Benghazi.
The rebels are negotiating with the town's tribal chieftains for its peaceful surrender.