Three people have been arrested for allegedly helping a suspect to escape following a knife attack on customs officers during a drug raid in To Kwa Wan on Thursday.

Two men, 27 and 41 years old, were arrested in Mong Kok early on Friday on suspicion of assisting offenders.

The third arrest was made on Friday afternoon, with a 66-year-old woman in Wong Tai Sin being taken in for allegedly misleading police officers.

The two men are understood to have allegedly arranged transport for the 38-year-old suspect, who remains at large and is the subject of an ongoing manhunt.

He is alleged to have attacked customs officers with a knife on Thursday during a drug raid in To Kwa Wan that ended with injuries to three of them.

The suspect was said to have refused to co-operate during the anti-narcotics operation and then attacked the three officers.

All three suspects have since been held for investigation.

Police have seized what appeared to be firearms, along with suspected drugs, from the flat that was raided.

Officers also found a 30-centimetre-long knife in a stairwell.