Rebels on the eastern front of Libya's civil war have lost 11 men in the past 24 hours fighting to capture the strategic oil terminal and refinery at Brega on the Mediterranean coast.
The rebels have taken the residential zone of New Brega, 15km from the terminal and port area.
They hope that capturing the port 750km east of the capital Tripoli will be a tipping point in their nearly six-month campaign to oust Colonel Gaddafi.
The rebels want to begin exporting oil from Brega as quickly as possible.
But the battle for it has been going on for months.
Troops loyal to Gaddafi were holding onto the oil facilities, firing rockets at rebel positions.
Gaddafi is clinging to power despite a near five-month-old NATO air campaign, tightening economic sanctions, and a lengthening war with rebels trying to end his 41-year rule.
The rebels have seized large swathes of the North African state, but are deeply divided and lack experience, and Thursday's gains in the east broke weeks of stalemate.
In the west, rebel forces driving north towards the town of Zawiyah, within striking distance of Gaddafi's stronghold in the capital, have not moved up from Thursday's positions.
UN's Ban Ki-Moon alarmed over civilian casualties
Meanwhile, UN Secretary-General Ban Ki-moon has expressed alarm over the rising number of civilian casualties in the Libya conflict, including those inflicted in NATO airstrikes.
Without specifically naming any side, Mr Ban called on 'all parties' to use 'extreme caution' in the battle.
He also stepped up calls for a political solution to the conflict, in which rebels have sought to overthrow Muammar Gaddafi's four-decades-old regime.
‘The secretary general is deeply concerned by reports of the unacceptably large number of civilian casualties as a result of the conflict in Libya,’ said the statement.
‘The secretary general calls on all parties to exercise extreme caution in their actions, in order to minimize any further loss of civilian life,’ it added.
When asked if NATO was included in the message, a UN spokeswoman stressed the ‘all parties’ phrase.
Mr Ban has been a staunch defender of the NATO air campaign against Gaddafi, which began in March.
But the air attacks have drawn harsh criticism from members of the UN Security Council, including Russia, China, Brazil, India and South Africa, who say the action goes beyond UN resolutions on Libya.
UNESCO's director general Irina Bokova this week branded as 'unacceptable' a NATO attack on the Libyan state broadcasting headquarters in which three people died, saying that media should not be targeted.
NATO has insisted that its attacks are in keeping with UN resolutions passed this year, which allow military action to protect civilians in Libya.
