Rush-hour attack at busy Hong Kong MTR station linked to triad feud over cannabis sales, police sources say

A knife attack that terrorised commuters at a busy railway platform during Monday's evening rush hour was believed to have been provoked by a long-standing dispute between two triad gangs, police sources said.

A dispute over the sale of cannabis sparked a series of fights between two factions of the Wo Shing Wo triad society in the past few months, one source with knowledge of the investigation said yesterday. Most fights had not been reported to police.

READ MORE: Three South Asian men treated for knife wounds

"One of the factions is understood to be active in Yuen Long and the other is active in Jordan and Yau Ma Tei," the source said.

Monday's attack at Jordan MTR station left three men, all asylum seekers from India, in hospital. The source said both gangs had recruited asylum seekers from South Asia. Last night, at least eight suspects who include Pakistanis, Indians and Nepalese people, remained at large.

To prevent revenge attacks, police have stepped up surveillance and raided venues where the gangs meet.

"The raids will continue over the weekend," another source said. "It is to deliver a message to them that police are monitoring them and action will be taken if they cause further trouble."