A woman and two teenagers bound for the United States and Canada have been arrested at Hong Kong International Airport after suspected pepper spray canisters and brass knuckles were found in their luggage.

Police said on Tuesday they had received three reports the previous day of suspected prohibited items discovered in a piece of checked luggage and two carry-on bags during security checks.

The trio were subsequently arrested after a preliminary investigation on suspicion of violating the Aviation Security Ordinance and the Firearms and Ammunition Ordinance.

The checked luggage, belonging to a 15-year-old girl bound for Canada, contained a prohibited item suspected to be brass knuckles.

Meanwhile, suspected pepper spray canisters were found in the carry-on bags of a 16-year-old and a 21-year-old woman headed for the US.

The three were released on bail pending further investigation.