A 33-year-old woman suffered a hand injury in a suspected utility-knife attack on Fung Nin Road in Yuen Long at about 9pm on 18 September.
Police said their preliminary investigation indicated that a man had pushed or collided with the woman from behind before attacking her with the knife. She was conscious when police and rescue personnel arrived, and was taken to Pok Oi Hospital before later being transferred to Tuen Mun Hospital.
Officers searched the area for the male suspect, whose whereabouts were unknown in the reports. The case was provisionally classified as assault occasioning bodily harm.
Police were continuing to investigate the motive and the fuller circumstances of the attack.