West Texas Intermediate futures for November delivery rose to $45.69 ( 1.33%), while Brent crude advanced to $48.83 ( 0.95%) as Russian air forces in Syria worried market participants.
Prices grew despite signs of slowing demand. China's official Manufacturing PMI contracted for the second straight month in September, although its reading was slightly above forecasts (49.8 vs 49.6). Meanwhile Caixin/Markit PMI fell to a fresh six-and-a-half-year low of 47.2.
Data by the Energy Information Administration showed that U.S. crude stocks rose by 4 million barrels to 457.9 million barrels in the week ended September 25. Economists expected crude inventories to remain unchanged.