Earlier, the US chief of staff for the mission in Libya insisted there had been no reports of civilian casualties caused by allied action.
Rear Admiral Gerard Hueber's comments came despite claims to the contrary by Col Gaddafi's government.
Operational control
Earlier, British Air Vice Marshal Greg Bagwell said Col Gaddafi's air force no longer existed as a fighting force.AVM Bagwell said the allies could now operate "with near impunity" over the skies of Libya and were now applying unrelenting pressure on the Libyan armed forces.
"We are watching over the innocent people of Libya and ensuring that we protect them from attack," he said. "We have the Libyan ground forces under constant observation and we attack them whenever they threaten civilians or attack population centres."
His comments came as Nato members debated who should lead the intervention, with the US keen to hand over operational control to Nato.
Nato members have been holding talks about assuming responsibility for the no-fly zone over Libya, so far without agreement.
Turkey is an integral part of the naval blockade, but has expressed concern about the alliance taking over command of the no-fly zone from the US.
UN Secretary General Ban Ki-moon has urged all sides in Libya to cease hostilities. "All those who violate international humanitarian and human rights law will be held fully accountable," his spokesman Martin Nesirky said.
US Defence Secretary Robert Gates is in the Egyptian capital, Cairo, for talks on both Libya and Egypt's hoped-for transition to democracy following the fall of Hosni Mubarak.
