Oil prices edged up on Thursday morning as investors worried about escalating tensions between the US and Iran, on fears that any attacks on Tehran or shipping could lead to supply disruptions. Brent crude oil futures were up 27 cents, or 0.39%, at $69.67 a barrel at 0350 GMT. US West Texas Intermediate crude rose 29 cents, or 0.45%, to $64.92. Both benchmarks settled higher on Wednesday.