New images have emerged showing the aftermath of an alleged NATO air raid targeting Tripoli's Nasser University. The attack reportedly left many university staff and students dead.
Libyan state television says dozens of others were also injured.
The UN Security Council Resolution 1973 has authorized the enforcement of a no-fly zone over Libya to protect civilians against forces loyal to Libyan ruler Muammar Gaddafi.
NATO has carried out many airstrikes in accordance with the UN mandate. However, many civilians have been killed in the attacks.
Meanwhile, clashes between revolutionary forces and Gaddafi loyalists intensified on Sunday.
At least seven people were killed in the town of Dafniya, near the besieged city of Misratah, Khaled Abu Falgha of Misrata's Hekma hospital said.
At least 15 revolutionaries and more than 100 Gaddafi forces were killed in the fighting in the western city of Zawiya, about 50 km (30 miles) from Tripoli, Ahmed al-Hawary, a spokesman for the revolutionary forces said.