Libya's rebels ramped up a pre-Ramadan offensive on Wednesday, pushing Muammar Gaddafi's troops into retreat in the east and preparing a fresh attack from the south of Tripoli.
Rebels said they had chased the bulk of Gaddafi's eastern army from the oil town of Brega while encircling loyalists holed up among oil installations in the northwest of the town.
As part of what now appears to be a countrywide effort to tighten the noose on Gaddafi before the Muslim fasting month of Ramadan begins around August 1, insurgents in the west said they were awaiting orders to start a fresh offensive from the Nafusa Mountains southwest of the capital.
During Ramadan, the endurance of even the hardiest volunteers will be tested by desert battle without food and water during the daytime fast observed by the faithful.
But at Brega, rebel gains were stymied by vast quantities of anti-personnel mines planted by retreating loyalist forces and the difficulties in attacking an estimated 200 Gaddafi troops fighting from positions near vital petrochemical facilities.
That difficulty was laid bare late on Tuesday, when 24 rebel fighters died. It was by far the rebels' bloodiest day since the battle for Brega began almost a week ago.
A rebel military source said many of the casualties came when troops closing in on isolated Gaddafi forces were hit by a line-guided rocket attack.
Outside the town, rebel troops cleared minefields holding up their advance, while trying to dislodge Gaddafi's artillery to the west.
Rebel military sources said some Gaddafi forces were arcing rockets over Brega down onto rebel positions from the town of Bishr, while most Gaddafi troops had retreated to Ras Lanuf, another oil town further west.
Libyan government spokesman Mussa Ibrahim has denied the rebels retook Brega.
"They tried to recapture the town, but were repulsed losing 500 of their fighters in the battle," Ibrahim said in Tripoli late on Monday.
The rebels said Gaddafi troops inside the town were largely conscripts and volunteers.
"The elite troops have withdrawn; they have left. The soldiers left in the city are stuck," said Abdulrazag Elaradi, a National Transitional Council (NTC) member visiting the front.
"They cannot go forward because they will be killed by the rebels and they cannot go back because they will be killed by Gaddafi's men."
Citing intercepted radio chatter, another rebel military source said many of the men had been left without vehicles and warned they would be shot if they retreat to Bishr.
Across the Gulf of Sirte, near the rebel-held enclave of Misrata, the picture was reversed.
There rebels said seven of their fighters were killed and 13 wounded when they repulsed a fresh Gaddafi attack.
"At least seven of our fighters were martyred and 13 others were wounded in intense fighting with loyalist troops," a rebels statement said.
Rebel commanders from Misrata met French President Nicolas Sarkozy on Wednesday to press for more support, French campaigner for the rebel cause, Bernard-Henri Levy, told AFP.
On the front line of the western desert hamlet Gualish, the rebels waited patiently in the shade until the next battle as Ramadan approaches and the searing summer sun grows more intense.
"We are preparing for the battle. We hope (it will take place), God willing, before Ramadan," or just after, said rebel commander Mokhtar Lakhdar.
"If there is fighting during Ramadan, we will fight as usual. We will not stop until we have liberated Libya," he said in Gualish, where the mercury hit 45 degrees Celsius (113 Fahrenheit) on Wednesday.
Lakhdar said the rebels were waiting for the green light from their headquarters in the eastern city of Benghazi.
Around him young rebels debated fighting during the fasting month.
"During Ramadan, it will be harder but, God willing, we will not be weakened but rather be stronger. Ramadan is a good time to be a martyr," said Shaban Aabor, 38.
The next rebel target is Asabah, 80 kilometres (50 miles) south of the capital, and the last barrier between rebels and the garrison town of Gharyan.
Western governments hailed tightening noose around Gaddafi.
"He's losing control of energy in his own country," French Defence Minister Gerard Longuet told journalists in Paris.
"A government that each day loses its international authority and ... control of territory should ask itself some questions," Longuet said.
White House spokesman Jay Carney said on Tuesday that the Libyan strongman was "cut off from fuel and cash."
Meanwhile Russia hosted Gaddafi's foreign minister Abdelati al-Obeidi on Wednesday for talks officials said were part of ongoing efforts to find peace, rather than aimed at threshing out a plan for Gaddafi to quit the country.