New York's main contract, light sweet crude for delivery in May, rose 15 cents to USD 105.55 per barrel while Brent North Sea crude for May gained 25 cents to USD 115.84.
"Basically it is just the spread of political instability. Over the weekend, it got a lot worse in Syria and Yemen," said Jason Feer, analyst for Argus Media energy market researchers in Singapore.
As Muammar Gaddafi's hometown was attacked by a coalition air raid, Libyan rebels pushed west to Tripoli yesterday and progressed towards Sirte, retaking towns they lost to government forces a week earlier.
Libyan rebels had promised that the uprising would not further hamper oil production in areas under their control, and the opposition plans to begin exporting oil "in less than a week", said a representative.
"We are producing about 100,000 to 130,000 barrels a day -- we can easily up that to about 300,000 (barrels) a day," Ali Tarhoni, the rebel representative responsible for economy, finance and oil, told a news conference at the weekend.
Oil-rich Libya was producing 1.69 million barrels a day before the unrest, according to the International Energy Agency. It is now producing 400,000 barrels a day.