Oil prices extend gains 

Oil prices rose on Thursday, driven by increasing concerns over potential military conflict between the United States and Iran as both countries stepped up military activity in the oil-producing region.

Brent futures were up 91 cents, or 1.3%, at $71.26 a barrel by 1058 GMT while U.S. West Texas Intermediate (WTI) crude gained 90 cents, or 1.4%, to $66.09.

Both benchmarks neared six-month highs on Thursday after advancing more than 4% on Wednesday as traders priced in the risk of supply disruptions in the event of conflict.

The latest rise in oil prices signals a market strengthening an already notable geopolitical risk premium as the world's most important oil artery again sits within striking distance of conflict, said Saxo Bank analyst Ole Hansen.

About 20% of global oil supply passes through the Strait of Hormuz.

Iranian state media reported that the country shut down the Strait of Hormuz for a few hours on Tuesday without making clear whether the waterway had reopened fully.    �"Reuters