"non essential" travel to eastern Libya.

"US citizens outside of Libya are urged to defer non-essential travel to Libya at this time," it added, citing the "potential for ongoing unrest."

"The US Department of State strongly urges US citizens to avoid all

demonstrations, as even peaceful ones can quickly become unruly and a foreigner could become a target of harassment, or worse."

But the agency responsible for US diplomacy also acknowledged that "there is no indication that Westerners are being threatened or targeted."

Protests against Moamer Kadhafi, the longest-serving Arab ruler, meanwhile spread closer to the capital Tripoli and new fighting erupted in the flashpoint city of Benghazi, while Human Rights Watch said at least 173 people had been killed since Tuesday in an iron-fisted crackdown.