As violence in Egypt continued, oil became more expensive again on international markets on Friday.
Benchmark crude for September deliveries rose by 12 cents to $107.45 (80.47 euros) per barrel in electronic trading on the New York Mercantile Exchange. The contract already surged by 48 cents to close at $107.33 a day earlier.
Brent crude, a measure used to price imported crude by many US refineries, rose by 5 cents to $109.77 per barrel, reflecting market experts' concerns about the political and economic situation in Egypt.
The ousting in early July of the country's president, Mohammed Morsi, had played a major role in lifting oil prices over fears of a supply disruption from the nation that controls the Suez Canal.
While Egypt itself is not a major oil exporter, traders worried that violence in the country could spill over to more important oil-exporting nations or affect major transport routes crossing Egypt.
Oil passed the psychologically significant $100 benchmark in early July for the first time since September last year. It reached an all-year high on July 19 as Libyan output fell drastically due to strikes at a number of facilities.
hg/mz (AP, dpa)