Brent and U.S. crude futures pushed higher on Friday, supported by the crises in Ukraine and Libya as well as positive economic data in the world's top two oil consumers, the United States and China.
Both Brent and U.S. crude posted weekly gains a second straight week.
Investors watched Ukraine, a main gas supply route to Europe from Russia, where presidential elections are set for Sunday after Kiev said more than a dozen servicemen were killed on Thursday in clashes with pro-Russian separatists.
Brent July crude rose 18 cents to settle at $110.54 a barrel, having swung from $110.25 to $110.67. Brent posted a 0.5 percent weekly gain, after rising nearly 2 percent the previous week, and Thursday's $111.04 intraday peak was the highest since March 4.
U.S. July crude rose 61 cents to settle at $104.35 a barrel, up 2.3 percent for the week.
"Geopolitical worries remain ahead of this weekend's presidential elections in Ukraine; clashes between rebels and Ukrainian forces continue," said Michael Poulsen of Global Risk Management.
"In Libya, there is uncertainty of the current oil output."
Libyan protesters on Thursday shut the headquarters of the company running the Brega oil port, the only eastern port to have remained open through most of the government's nine-month stand-off with a rebel group.
Positive U.S. and Chinese manufacturing data released on Thursday boosted optimism for future oil demand growth and propped up prices.
"The bulk of fresh news that has flowed into the energy complex this week has fallen decidedly in a bullish direction and is tending to increase the likelihood of some upside price follow through early next week," said Jim Ritterbusch, president at Ritterbusch and Associates in Galena, Illinois.
Manufacturing growth in the United States picked up to a three-month high in May, while China's factory sector turned in its best performance this year in May.
Sales of new U.S. single-family homes rose more than expected in April, the U.S. Commerce Department said on Friday, bolstering hopes the sputtering housing recovery may start to pick up.
The multimillion-barrel drop in U.S. crude inventories last week registered in both government and industry data also was cited as helping keep crude futures supported.
Money managers raised their net long U.S. crude futures and options positions in the week to May 20, the U.S. Commodity Futures Trading Commission said on Friday.
The speculator group raised its combined futures and options position in New York and London by 13,532 contracts to 363,863 during the period.
(By Robert Gibbons; Additional reporting by Peg Mackey in London and Jacob Gronholt-Pedersen in Singapore; Editing by William Hardy, David Evans and Chizu Nomiyama)