GENEVA - More than 8,000 people have fled fighting around Libya's capital, half of whom have been displaced over the last two days, the United Nations said Friday.

"Displacements from areas affected by the clashes in an around Tripoli continue to surge," UN spokesman Rheal Leblanc told reporters in Geneva.

Aside from those who have fled, Leblanc said that "many families remain stranded inside conflict-affected areas," with safety fears rising and supplies running short.

Military strongman Khalifa Haftar has launched an offensive to take Tripoli from the UN-backed Government of National Accord (GNA), intensifying the crisis in the country driven by divisions since the NATO-backed overthrow of dictator Moamer Kadhafi in 2011.

Dozens of people have been killed over the past week and more than 300 have been wounded, according to the World Health Organization.

Speaking by phone from Tripoli, WHO's representative in Libya Jaffar Hussain Syed told reporters that the "fighting is closing (in) from the outskirts to inside of Tripoli"

"Our fear is that there will be more civilian casualties," he said.

Haftar's advance has triggered mounting global alarm, with the UN warning the situation could spiral out of control.