Hong Kong's Consumer Price Index (CPI) fell to 3.9 percent year-on-year in May from 4.0 percent in April, mainly due to the smaller rise in the prices for fresh vegetables, the city's statistics department said here on Thursday.

Netting out the effects of the government's one-off relief measures, the year-on-year CPI in May was 3.8 percent, compared to 3.9 percent in April.

Amongst the various CPI components, prices for housing in May rose 6.1 percent from a year ago, followed by the prices for electricity, gas and water 5.9 percent, food 3.6 percent, miscellaneous services 3.1 percent, transport 2.3 percent, alcoholic drinks and tobacco 1.6 percent and clothing and footwear 0.7 percent.

On the other hand, prices for durable goods fell 4.8 percent from a year ago.

A government spokesman said Hong Kong's inflation is expected to face some mild upside risks in the coming months as the lagged effects of the rise in private housing rentals during 2012 continue to feed through.

Nonetheless, the subdued imported inflation and the recent milder increase in housing rentals in the market for fresh lettings should help contain inflation in the latter part of this year, he said.