Police arrested five men and one woman aged between 20 and 26 at a suspected vice den in Yau Ma Tei in Kowloon on Tuesday.
Acting on a tip-off, police officers raided a flat at 313 Nathan Road in Yau Ma Tei at 2pm and arrested six people, comprising one man of Indian origin, with the others of Nepalese origin, Sing Tao Daily reported.
Two 43-centimeter-long melon knifes, a 33-cm-long Nepalese kukri knife, two sharpened steel poles and a meth-smoking device were seized at the flat.
Police also confiscated two signal grenades in the flat. These were sent to the Explosive Ordnance Disposal Bureau for further investigation.
The six people were arrested on suspicion of possessing offensive weapons and ammunition, and also drug equipment drug, Oriental Daily reported.
An Anti-triad unit from the Kowloon West police division is following up the case.