Libya's opposition leaders have said that at least 10,000 people have died since the start of the conflict in February.
Al Jazeera's correspondent, Mike Hanna reporting from Benghazi, said: "Given the intensity of the conflict, it doesn't come as a surprise.
"We have focused on areas like Misurata, where the humanitarian crisis is well documented, however it is happening throughout Libya, the full extent of the crisis is not known and there is no real idea of (casualty) figures."
The United Nations says it has been guaranteed humanitarian access to Misurata, while Britain says it will fund efforts to evacuate thousands of stranded migrant workers by boat from the besieged port city.
A Libyan official told Valerie Amos, the UN humanitarian chief, that Muammar Gaddafi's government was willing to set up "safe passage" out of the city, which remains partially in opposition hands after weeks of attacks by Gaddafi loyalists.