Crude oil prices were up to begin Friday to continue their gains from the previous session after the attacks on oil tankers in the Gulf of Oman intensified fears of secure supply of oil from the Middle East.
International benchmark Brent crude was trading at $61.69 per barrel at 0521 GMT for a 0.5% gain after closing Thursday at $61.36 a barrel.
American benchmark West Texas Intermediate (WTI) was at $52.45 a barrel at the same time for a 0.7% increase after ending the previous session at $52.09 per barrel.
Brent crude climbed above $62 per barrel on Thursday, while WTI was above $53 a barrel after two oil tankers were attacked in the Gulf of Oman near the world's largest oil transit chokepoint the Strait of Hormuz.
The attacks came after a month when four tankers were attacked in the region, and intensified worries that the secure supply of oil from major oil exporters such as Saudi Arabia and the United Arab Emirates could be under threat.
U.S. Secretary of State Mike Pompeo blamed Iran for the attacks on Thursday, describing them as part of "an unacceptable campaign of escalating tension by Iran."
The U.S. blamed Iran in May for attacks on oil tankers off the coast of the United Arab Emirates, while Tehran denied the accusations.
Tensions between Washington and Tehran escalated after the U.S. President Donald Trump administration has adopted "zero tolerance policy" against Iran, reimposing sanctions on its oil exports that is crucial for Iran's economy.
By Ovunc Kutlu