KARACHI: An oil pipeline of the National Oil Refinery started leaking in Khayaban-e-Sehar, Defence Housing Authority, on Saturday evening, with a street submerged in the flowing fuel.Responding to reports, police personnel soon arrived on the scene and cordoned off the area by sealing all surrounding streets.They also advised worried residents not to get closer to the affected street. Efforts were continuing into the night to fix the leaking pipleline.