Officers said the incident happened some time between 1.30pm and 2.30pm on Thursday, August, 6. The assault is reported to have happened on Pendle Way, Gannow Lane, the subway connecting those two streets and the Adamson Street and St John's Road area. The girls managed to flee and contact someone for help and an investigation is under way, police said. A 59-year-old man has been arrested on suspicion of sexual assault. "If you have CCTV, dashcam or mobile phone footage that covers the area, we would be very interested in seeing it.