Police fear possible gang warfare after a brawl between two alleged gangsters and a group of Nepali men in Yau Ma Tei yesterday.
A constable drew his revolver to stop the fight, which broke out in Temple Street in the early morning.
Four local men - two Hong Kong Chinese and two Nepalis - were arrested after they wrestled with police. The officers were unhurt but the suspected gangsters were injured. A 38cm-long knife and several bloodstained iron bars were found at the scene.
Officers were called after eight or nine men started fighting in Temple Street near the junction with Nanking Street shortly after 7.30am.
Two suspected 14K triad members encountered six or seven Nepalis after drinking heavily at a nearby pub, according to police. The Nepalis were drinking and chatting outside a convenience store.
A police patrol van that drove past pulled over after hearing people shouting at the scene. As three officers from Kowloon West emergency unit jumped out of the van, some of the men ran off.