Hong Kong Express said on Monday that it's cancelling some flights between the SAR and Japan in the first half of February, citing restrictions imposed by Japanese authorities.

Flights affected include those to and from Okinawa, Osaka-Kansai, and the Narita and Haneda airports in Tokyo between the 1st and 15th next month.

The budget airline said on social media that passengers who made a booking with them directly will be notified in the coming days, and they will be given options to change their flights, or seek a full or partial refund depending on the type of tickets they have.

"There is no need for passengers to contact us via our customer connect team," the company said in the statement, while thanking passengers for their patience and understanding.

"We will continue to work hard to maintain our schedule as much as possible to minimise the impact to our customers."