Oil prices moved higher on Monday following a weekend of turmoil in key petroleum producers Libya and Iraq.
US benchmark West Texas Intermediate for September delivery snapped a five-day losing streak, gaining 41 cents to $98.29 a barrel on the New York Mercantile Exchange.
European benchmark Brent oil for September delivery rose 57 cents to $105.41 a barrel in London.
The rally came on continued violence in Libya, where at least 22 more people died in clashes in Tripoli over the weekend, lifting the death toll to 124 since July 13 with more than 500 wounded.
Analysts have said the violence threatens efforts to restore oil production in the North African country.
Fighting also raged on in Iraq, where Baghdad's air force and Kurdish fighters from Syria joined forces with Iraq's embattled peshmerga to push back jihadists whose latest attacks sent thousands of civilians running for their lives.
Sunni militants have also seized two small oilfields in Northern Iraq which a North Oil Company official said had a combined capacity of 20,000 barrels per day.
"During the entire weekend, the newswires were filled with violence in the Middle East, whether it was Iraq or Libya," said Andy Lipow of Houston energy consultancy Lipow Oil Associates.
"The combination of these events starts putting a pull on the crude oil price."
US oil prices last week sank to six-month lows on concerns about anemic growth in US demand for gasoline during the summer driving season.
Lipow said traders remain cautious on US gasoline demand, but that continued violence in key oil producing regions could "easily" push oil prices back up.