ZAWIYAH, Libya Libyan rebels seized an oil refinery in the city of Zawiyah and took control of Sabratha further west on the main highway from Tripoli to Tunisia as NATO aircraft struck targets in the capital. 
 
 Air strikes rocked Tripoli several times during the day, witnesses said. The targets were not immediately identified. 
 
 The government of Libyan leader Muammar Gaddafi appeared to be increasingly isolated in its stronghold. But government spokesman Moussa Ibrahim, speaking on state television, said: "We reassure people that we are making progress on all fronts." 
 
 A government official said Ibrahim's brother, Hasan Ali, had been killed by NATO Apache helicopter gunships. He said the 25-year-old student had gone with a group to check on friends in Zawiyah -- now under rebel control -- after hearing reports of fighting there. He died in the central square. 
 
 "We are surprised by this and we condemn it. NATO planes have become a way of killing civilians and providing air cover for rebels to advance on Libyan cities," the official said. 
 
 West of Tripoli Thursday, some 200 rebel fighters firing guns in the air celebrated the capture of Sabratha 80 km (50 miles) after a four-day battle. 
 
 Fighters said the rebels control 90 percent of the ancient Roman town, a UNESCO World Heritage site. Securing Sabratha would tighten their control over supply lines from Tunisia, which were cut at Zawiyah this week. 
 
 A local man said the breakthrough came after NATO bombed a military facility in Sabratha and rebels seized weapons. 
 
 Rebel advances in recent days have cut off Gaddafi's forces from their main resupply routes, ending a long stalemate and putting Gaddafi's 41-year rule under unprecedented pressure. 
 
 "BODIES IN THE STREETS" 
 
 But insurgents in the east, where casualties have been high, suffered a setback when a group planning to mount an uprising in government-held Zlitan were preempted by Gaddafi forces. 
 
 "There are still bodies in the streets. The situation is very difficult. It was a preemptive attack by Gaddafi's forces," an anti-government activist called Mohammed told Reuters by telephone from the town, west of the rebel-held port of Misrata. 
 
 Four people were killed and five badly wounded when Gaddafi's troops attacked rebels who aimed to stage a "mini" revolt to coincide with a push from Misrata, he said. 
 
 Despite denials, the rebels and Gaddafi loyalists are in negotiations, former French premier Dominique de Villepin said. 
 
 He told the daily Le Parisien he held "extremely difficult" talks with both Monday, in the Tunisian resort of Djerba. 
 
 "I was indeed there, but I cannot make any further comment because it would compromise the chances of success," he added. 
 
 The whereabouts of Gaddafi, 69, are unknown. 
 
 CASUALTIES MOUNT 
 
 After a two-day battle, rebel fighters occupied Zawiyah refinery, 50 km west of Tripoli, and raised their flag. 
 
 "We took control last night," said Saleh Omran, 31, a fighter from Zawiyah. He said the insurgents fought about 150 Gaddafi troops, who finally fled by sea in inflatable boats. 
 
 Doctors at a hospital near Zawiyah said nine people were killed and at least 45 injured in fighting around the town and at the refinery Wednesday, most of them rebels. 
 
 In Geneva, the International Committee of the Red Cross (ICRC) said health care facilities in Libya were being attacked or misused for military purposes by both sides in the conflict. 
 
 The ICRC expressed concern at a rapid deterioration in the humanitarian situation -- as well as mounting casualties -- in and around Brega, Zawiyah, Garyan, Sabratha and Misrata. 
 
 "On Tuesday, in Brega, our delegates saw several ambulances hit by bullets," said Georges Comninos who heads the ICRC team in Tripoli. "This is seriously compromising the delivery of health care to the wounded and sick." 
 
 SOUTHERN FRONT 
 
 Rebels also held Garyan, a strategic crossroads town 80 km inland from Tripoli on a main highway south. 
 
 "We took one tank and an anti-aircraft gun from Gaddafi's forces. Next, we'll go to Tripoli," one fighter told Reuters in Garyan, where the captured weapons sat in the town square. 
 
 On the eastern front, the insurgents said they had tightened their grip around the oil port of Brega, but had suffered high casualties in fighting over the past several days. 
 
 "All of Alargop is now free, liberated," spokesman Musa Mahmoud al-Mugrabi said of an area 6 km south of Brega, on a supply route for Gaddafi's forces running south. 
 
 About 40 rebels have been killed and nearly 100 wounded in and around Brega over the past 10 days, according to a tally of reports from the rebels and hospital workers. 
 
 "Casualties have been very high because it's urban clashes," al-Mugrabi said. 
 
 Gaddafi seemed isolated as forces determined to topple him close in, vowing to enter Tripoli by the end of the month. 
 
 Libyan Prime Minister Al-Baghdadi Ali Al-Mahmoudi declined to comment on any talks other than to say the government has been in contact with all sides. 
 
 "You will hear in the next few days good news that will make you happy if you are for peace," he said. 
 
 (Additional reporting by Robert Birsel in Benghazi, Missy Ryan in Tripoli, Michael Georgy in the Western Mountains, Hamid Ould Ahmed in Algiers, Souhail Karam in Rabat; Joseph Nasr in Berlin, Alexandra Sage in Paris; Stephanie Nebehay in Geneva; Writing by Douglas Hamilton; Editing by Michael Roddy) 

 Explosions heard in Tripoli as rebels capture key towns and supply routes, further isolating Gaddafi's stronghold. 
 
 Rebel forces also claim to have seized a military base in Gharyan, which lies on a strategic supply route [Al Jazeera] Libya's opposition fighters claim to have taken control of a strategic oil refinery in the western town of Az Zawiyah and also to have blocked the main highway north to the capital, Tripoli. "The battle [for the refinery] lasted for two days but the main battle was last night. We took control last night," Saleh Omran, a rebel fighter from Az Zawiyah told the Reuters news agency on Thursday from inside the refinery complex. He said rebel fighters forced the troops of Colonel Muammar Gaddafi to flee the seaside refinery, a major source of fuel for the loyalist troops in Tripoli. The refinery complex, located about 50km west of the capital along the highway linking Tripoli to Tunisia, was reportedly under rebel control on Thursday. Rebel forces also claimed to be in control of the town of Surman, 60km west of Tripoli, and Gharyan, 50km to the south, days after claiming to occupy Az Zawiyah. Doctors at a hospital a few kilometers south of Az Zawiyah said nine people were killed and at least 45 injured in fighting around the town and at the refinery on Wednesday. 
 
 
 
 Control of the road between Surman and Az Zawiyah would be easier for opposition fighters to cut supply routes to the capital, further isolating Gaddafi's stronghold. Explosions heard in Tripoli Several explosions rocked Tripoli early on Friday as NATO warplanes flew over the capital. A slew of explosions were heard around 1:00 am (2300 GMT) in the heart of the seaside capital where Gaddafi's residential complex is located, as well as in several areas in the west of the city. On Thursday, central Tripoli and the eastern suburb of Tajura were targeted by NATO warplanes, according to witnesses. Click here for more of Al Jazeera's special coverage Moussa Ibrahim, the Gaddafi spokesman, played down rebel gains and said the government remained in control of the country. "This is a crisis that will last a few days and then it will be - God willing - overcome," Ibrahim was quoted as saying by the JANA news agency on Thursday. On the eastern front, fighting continued as both sides try to gain control of the oil town of Brega. "All of Alargop is now free, liberated," Musa Mahmoud al-Mughrabi, the rebel spokesman, said of the area 6km south of Brega. "Casualties have been very high because it's urban warfare," he said. About 40 rebels have been killed and nearly 100 wounded in and around Brega over the past 10 days, according to a tally of reports from the rebels and hospital workers. Aided by NATO bombers, assault helicopters and a naval blockade, the rebels have transformed the battle in the last few days after many weeks of stalemate. The US also deployed two more Predator drones for surveillance operations over Libya, a US official said on Wednesday. It was unclear how many drones the US already had over the country.
– This one sounds like a serious blow to Moammar Gadhafi: Rebels have taken control of the port city of Zawiyah and its all-important oil refinery, report the New York Times and Reuters. The rebels routed Gadhafi's troops last night, evident by the uniforms seen scattered about today by deserting government soldiers. The refinery, located only 30 miles from Tripoli, had been an important source of fuel for Gadhafi's troops. Rebels also have claimed control of other cities surrounding the capital, notes al-Jazeera, but a Gadhafi spokesman downplayed the situation. "This is a crisis that will last a few days and then it will be—God willing—overcome," he said today. A rebel fighter in Zawiyah had a different view: "We took one tank and an anti-aircraft gun from Gadhafi's forces. Next, we'll go to Tripoli."