Police searched across Diamond Hill and Tsz Wan Shan on October 4 after reports of a woman carrying and wielding a ceramic fruit knife about 8 inches long at or near Diamond Hill Station. The search began around the station and a nearby shopping centre, where counter-terrorism officers were seen carrying shields.
Police later suspected that the woman had gone to Tsz Ching Estate and sent officers to search Ching Fai House. Some officers took breaching equipment upstairs as they searched the building. Ming Pao reported that officers also searched Lung Poon Court and that no one had been injured at that stage of the incident.