Oil prices rallied towards $65 per barrel on fears of a US military attack on Iran.
Brent crude was up 42 cents, or 0.66 percent, at $64.87 a barrel by 0850 GMT. The global benchmark jumped 4.3 percent on Thursday and was up around five percent for the week, in its first weekly gain in five weeks.
US West Texas Intermediate crude was up 21 cents, or 0.38 percent, at $57.28 a barrel. The US benchmark surged 5.4 percent on Thursday and was on track for a 9 percent increase this week.
"Crude prices are spiking on increased Middle East tensions after Iran shot down a US drone in what the US claims is international airspace," said Jason Gammel from Jefferies.
Iran said it had shot the drone over its territory.
Tensions have been on the rise because US sanctions on Iran have severely reduced oil exports from the country and Washington has blamed Tehran for a series of attacks on oil tankers in the Gulf.
"There is no doubt that a severe disruption to the transit of oil through this vulnerable route would be extremely serious," said consultancy FGE Energy in a note.
