Pakistan, Aug. 15 -- Oil prices rose on Friday and were on track for weekly gains after the United States threatened an indefinite naval blockade of Iran, raising concerns about disruptions to crude supplies from the Middle East.

Brent futures were up $1.43, or 1.64%, to $88.50 a barrel at 0810 GMT, while US West Texas Intermediate crude futures were up $1.56, or 1.92%, to $82.81 a barrel.

Higher oil prices are a natural result of the latest approach by the US, which implies a substantial extension of the trouble in the Middle East with little hope of a near-term resolution, said Bjarne Schieldrop at SEB Research.

On Thursday, the US warned it could maintain a naval blockade of Iran indefinitely and ramp up economic pressure on Tehran ...