美参谋长：利比亚空袭“未伤及平民”
The US chief of staff for the mission in Libya has insisted there have been no reports of civilian casualties caused by allied action.
美国打击利比亚行动参谋长强调，此次联合行动尚未造成平民伤亡。
Western aircraft have flown hundreds of sorties over Libya
Earlier, British Air Vice Marshal Greg Bagwell said Col Gaddafi's air force "no longer exists as a fighting force".
Latest reports from Libya speak of an explosion at a military base in the Tajura region east of Tripoli.
There were also reports that government tanks had shelled the hospital in the rebel-held western city of Misrata.
Witnesses had earlier said the tanks encircling the city had pulled back from their positions under air assault from international forces.
And there is also said to have been fierce fighting between rebels and pro-Gaddafi forces in the strategic eastern town of Ajdabiya. Residents fleeing the town described shelling, gunfire and houses on fire.
Operational control
Rear Admiral Hueber was speaking to reporters by phone from the command ship USS Mount Whitney in the Mediterranean.
"We are putting pressure on Gaddafi's ground forces that are threatening cities," he said. Asked if that meant air strikes, he replied: "Yes."
He continued: "Our mission here is to protect the civilian populace and we choose our targets and plan our actions with that as a top priority."
He added that allied aircraft had flown 175 sorties in the last 24 hours - 113 of them by US aircraft.
His comments came as Nato members debated who should lead the intervention, with the US keen to hand over operational control to Nato.
AVM Bagwell said the allies could now operate "with near impunity（无患，免责） " over the skies of Libya.
Speaking during a visit to RAF aircrew based at Gioia del Colle in southern Italy, he said they 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."
US Secretary of State Hillary Clinton has again urged Col Gaddafi to step down and leave Libya.
UN Secretary General Ban Ki-moon has urged all sides in Libya to cease hostilities（战争，敌意） . "All those who violate（违反，侵犯） international humanitarian and human rights law will be held fully accountable," his spokesman Martin Nesirky said.