Forces loyal to Muammar Gaddhafi's loyalists shelled a mountain town and clashed with opposition forces in a besieged coastal city today as the Libyan leader sought to quell resistance in the western part of the country that is largely under his control.
France and Italy, meanwhile, promised more support for Libya's opposition, saying they would join Britain in sending military advisers to help the rebels break a battlefield stalemate. France said it would also intensify airstrikes against Libyan military targets after a month of Nato airstrikes failed to rout Gaddafi's forces.
In Geneva, the UN's top human rights official said Libyan government forces may be committing war crimes by using heavy weapons against civilians in the besieged port city of Misrata. Navi Pillay said Gaddafi's troops should be aware that their actions will be scrutinized by the International Criminal Court.
Fighting in Libya erupted two months ago, when protests against Gaddafi's four decades in power turned into an armed uprising. Rebels now control most of the east, while Gaddafi holds most of the west. However, there are rebel-held areas in western Libya, particularly the Nafusa mountain area that is home to Libya's Berber minority.
Since the weekend, the Nafusa region town of Yifran, with a population of about 25,000, has come under daily attack with Grad rockets, tank shells and anti-aircraft guns, said a rebel fighter.
The fighting in the mountain region has sent thousands fleeing into nearby Tunisia.
In Yifran, doctors had to abandon the town's hospital because of the shelling. Qalaa has also come under attack.
International aid officials said more than 10,000 people from the Nafusa mountain area have fled to Tunisia in recent days, avoiding official border crossings manned by Gaddafi loyalists.
New clashes erupted today in the other rebel outpost in western Libya, the city of Misrata.
Exchanges of fire were heard between Libyan troops and armed residents in the city centre. Nato planes flew overhead, but did not carry out airstrikes.
The rebels control the port area, while Gaddafi's forces have deployed along Tripoli Street, a downtown thoroughfare.
Misrata has been under siege for nearly two months. In recent days, Gadhafi's forces have intensified their assault on the city, firing tank shells and rockets into residential areas, according to witnesses and human rights groups.
Pillay, the UN human rights commissioner, urged Libyan authorities to halt their siege of the city and allow medical care to reach victims. Pillay says it is "clear that the numbers (of casualties) are now substantial, and that the dead include women and children".
Hundreds of migrant workers and wounded people have been evacuated by boats, which have also delivered humanitarian supplies, including food and medicine.