| ZAWIYAH, Libya
ZAWIYAH, Libya Libyan rebels fought fierce battles in two coastal cities on either side of the capital Tripoli on Friday in a drive to topple Muammar Gaddafi, but met stiff resistance from forces loyal to the long-time leader.
Sustained blasts from rocket-propelled grenades, mortars and anti-aircraft guns rang out in the center of Zawiyah, a city on the coastal highway 50 km (30 miles) west of Tripoli that the rebels entered this week, in a clash that killed at least two.
As they pushed to consolidate control of the city and its strategic oil refinery, rebels in Zawiyah's central square exchanged heavy fire with Gaddafi forces holed up inside a nearby hospital before driving them out, Reuters witnesses said.
East of Tripoli, opposition forces fought bloody street battles in the city of Zlitan but suffered heavy casualties, a Reuters reporter there said. A rebel spokesman said 32 rebel fighters were killed, with 150 wounded.
Rebel advances have cut off Tripoli from its main supply routes, putting Gaddafi's four-decade rule under heavy pressure.
But Gaddafi's information minister, Moussa Ibrahim, said late on Friday the government's military retained the upper hand and scorned what he described as 'bands of insurgents'.
With rebels pushing on the ground, NATO has pressed on with its campaign from the air and its warplanes pounded targets in the capital overnight.
Gaddafi's government has blamed NATO bombings for scores of civilian deaths and said 27 people were killed in the most recent raids on Tripoli. NATO accuses Gaddafi forces of housing military assets near civilians.
In another sign the fighting is hitting closer to Gaddafi's inner circle, the brother of the spokesman who has served as the Tripoli government's public face was reported killed in a front line city. The government blamed NATO attack helicopters.
Libyan officials separately brought journalists to a residential district where a compound of several large buildings was blasted to pieces. Neighbors said it belonged to Abdullah al-Senussi, Gaddafi's brother-in-law and head of intelligence.
NBC News reported Gaddafi was making preparations to leave Libya with his family for possible exile in Tunisia, but that it was unclear if he would follow through. NBC said the information came from U.S. officials who cited intelligence reports.
A spokeswoman for the International Organization for Migration (IOM), Jemini Pandya, said the operation to rescue thousands of Egyptians and other foreigners trapped in Tripoli by the latest fighting would begin within days.
"We are looking at all options available, but it will probably have to be by sea," she told a Geneva news conference.
More than 600,000 of up to 2.5 million foreigners, mostly Asian and African migrant workers, have fled Libya in six months of fighting. But thousands remained in Tripoli, which until this week was calm and a safe two-hour drive from Tunisia.
The route has been cut since the rebels entered Zawiyah, which lies on the coastal highway, six days ago. In Zawiyah, medics at another local hospital said two dead and three wounded had been taken there from the recent fighting.
On Thursday they took the neighboring town of Sabratha, and on Friday they seized the nearby town of Surman.
Several hundred rebels and their supporters gathered on the streets of Surman, just off the highway, to celebrate the victory, flying the rebel green, red and black flag.
"SENUSSI HOUSE" HIT
In Tripoli, Omar Masood, an oil engineer who lives across the street from the compound that was destroyed, said it had been struck before dawn and belonged to Senussi, one of the most senior figures in Gaddafi's leadership.
A large building had been reduced to rubble. The grounds appeared to be grand, with a fountain and children's swing set and a garden with a live gazelle standing amid the ruins. Officials could not say if it was Senussi's house or whether he was present at the time.
Senussi, who is married to Gaddafi's sister, is one of three figures along with Gaddafi and his son Saif al-Islam wanted by the International Criminal Court for war crimes. The court's prosecutor blames him for killing civilians.
A government official said the brother of Moussa Ibrahim -- the spokesman whose briefings have been broadcast worldwide throughout the six-month-old uprising -- was killed by a NATO helicopter gunship in the central square of Zawiyah.
A Reuters reporter at the front east of Tripoli said rebels had launched an assault on Gaddafi's forces in Zlitan, the closest front line east of the capital. Many wounded were being brought to the rebels' field hospital.
"Battles began in the early hours of today and the rebels have liberated most of Zlitan," rebel spokesman Gemal Salem said by telephone. "Now the fighting is in the west of Zlitan."
(Additional reporting by Missy Ryan in Tripoli; Robert Birsel in Benghazi, Libya; Stephanie Nebehay in Geneva; Ulf Laessing in Garyan, Libya; Mariam Karouny in Beirut; William Maclean in London; and Souhail Karam in Rabat; Tarek Amara in Tunis; Writing by Richard Valdmanis and Peter Graff; Editing by Maria Golovnina)