Duty-free items can be carried on board in case of purchased after passing the security checkpoints and under the limit of carry-on baggage.
Reference
For Internetional flights, it is not allowed to carry on liquids over 100ml. However, liquids over 100ml can be carried onboard if they are unopened duty-free items and purchased after passing through the security checkpoints.
Please click the link below for more information about carry-on baggage.
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