WASHINGTON – The United States on Monday ordered all non-essential staff to leave Libya and warned US nationals to avoid travel to the north African country as anti-government protests raged.

"The Department of State has ordered all embassy family members and non-emergency personnel to depart Libya," a statement said. "US citizens outside of Libya are urged to defer all travel to Libya.

Protesters Monday overran several Libyan cities while regime stalwarts began defecting as the pillars of Kadhafi's hardline rule were targeted in the capital Tripoli amid reports he had fled the country.

Cities including Benghazi in the east had fallen to demonstrators opposing Kadhafi's 41-year-old regime after military units deserted their posts, said the Paris-based International Federation for Human Rights (IFHR).

With hundreds of protesters reportedly killed, the US State Department's travel advice urged Americans not to visit while there was a continued threat of violence and suggested those already there hunker down.

"US citizens in Libya should minimize overall travel in-country, exercise extreme caution when traveling, and limit all travel after dark. US citizens not departing Libya should make preparations to shelter in place," it said.

Americans should avoid areas where demonstrations are likely to occur and should not be tempted to participate in protests, even if they appeared peaceful, the bulletin said.

"Spontaneous demonstrations, violence, and looting are possible throughout the next several days," it said.

"Demonstrations have degenerated on several occasions into violent clashes between security forces and protesters, resulting in injuries and deaths."