Oil prices fell slightly on Friday, but were on track for a second weekly rise as the stalemated US-Iran war continues to disrupt supply from the key Middle East producing region. Brent crude futures fell 23 cents, or 0.3%, to $93.55 a barrel by 0142 GMT, after climbing 2.4% in the previous session. US West Texas Intermediate crude futures slipped 33 cents, or 0.4%, to $86.50 a barrel, after