Rebels are holding out in part of the strategic oil port of Ras Lanouf after fierce fighting with Muammar Gaddafi loyalists in central Libya.
The Libyan leader's forces took the residential part of Ras Lanouf in yesterday's battles, said Ibrahim Said, the deputy director of the hospital in the nearby city of Ajdabiya.
But he said rebels continue to hold the port's industrial areas and oil facilities.
Four dead and more than 40 wounded from the fighting were brought to Ajdabiya hospital.
In Thursday's battles, government forces rained a barrage of rockets, artillery and tanks shells down on the opposition-held port, driving many of the rebel forces into a frantic retreat further east.
The opposition, however, made some diplomatic gains. France became the first country to recognise the rebels' eastern-based governing council, and an ally of President Nicolas Sarkozy said his government was planning "targeted operations" to defend civilians if the international community approves.
US Secretary of State Hillary Rodham Clinton said she would meet opposition leaders in the US, Egypt and Tunisia.
In Tripoli, Gaddafi's son Saif al-Islam vowed to retake the eastern half of the country, which has been in opposition hands since early in the three-week-old uprising.
"I have two words to our brothers and sisters in the east: We're coming," he told a cheering crowd of young supporters. The son depicted Libyans in the east as being held "hostage" by terrorists.
Gaddafi's government sent a text message to Tripoli residents, warning imams at mosques against allowing protests after Friday prayers. The message quoted Saudi cleric Sheik Saleh Fawzan, a member of the Saudi Supreme Scholars Council, as saying it was "unacceptable" for any imam "who incites people (or) causes disturbances of the society in any mosque."
There were demonstrations after prayers for the past two Fridays, and militiamen used tear gas and live ammunition to disperse the crowds who had gathered in mosques. There were an undetermined number of deaths after the February 25 demonstrations.
The retreat was a heavy blow for the ragtag rebel forces of armed civilians and mutinous army units that only days before had confidently charged west, boasting they would march the hundreds of miles to "liberate" Tripoli.
There were no concrete signs of Western moves toward military assistance that the opposition has been pleading for. A rebel spokesman went beyond repeated calls for a no-fly zone to prevent Gaddafi's air force from harrying opposition fighters and said the West should carry out direct strikes against regime troops.
"We have requested for all steps to be taken to protect the Libyan people. We believe the UN can do that. The bombardment of mercenaries and Gaddafi troop camps are among our demands," Abdel-Hafidh Ghoga, a spokesman of the governing council, told reporters in the opposition's eastern bastion of Benghazi.