Hong Kong airport, the world's fifth busiest international passenger hub, will start screening liquids, gels and aerosols in carry-on baggage in March to bring it in line with international practices, the government said in a statement.

All liquids, gels, aerosols in cabin baggage must be carried in containers with a capacity not greater than 100 ml (3.520 fl oz) and the containers have to fit comfortably in a transparent re-sealable plastic bags no larger than one 1 litre (0.22 Imp gallons), the new rules say.

Exceptions will be made for medications, baby milk and food and special dietary requirements subject to verification, it said.

The security bureau on Wednesday declined to say whether there had been any specific threats, and the police did not have an immediate comment, but the government statement, issued on Tuesday evening, said the rules were being implemented to bring Hong Kong in line with the new guidelines of the International Civil Aviation Organization (ICAO).

After a plot to smuggle liquid explosives onto planes was foiled in Britain last year, several airports and airlines around the world -- particularly in Europe and the United States, introduced new restrictions on what passengers can carry in their hand luggage.

In the 12 months through January, 44.5 million passengers came through Hong Kong airport.