Police in Hong Kong have increased security measures ahead of another clampdown planned on road and rail links by anti-government protesters.
Only passengers are being allowed into the airport building or to use the Airport Express, boarding in downtown Hong Kong.
The train is not stopping en route on the Kowloon peninsula.
The protest is the latest in 14 weeks of demonstrations in the city.
The measures are aimed at avoiding the chaos of last weekend, when protesters blocked airport approach roads.
Protesters also occupied the arrival hall last month, halting and delaying flights.

Russia hits Ukraine with drones and missiles, killing at least eight
Kagan and Soai win 2026 Nobel chemistry prize for single molecular mirror creation
Seven injured in Polish school knife attack, police say
Israelis mark three years since Hamas attack that set off Gaza assault
Houthis launch missiles at Yemen's Aden airport as fighting intensifies
Russia says tanker crew rescued in Black Sea after attack set ship ablaze
Kenya confirms first Ebola case
UK police make further arrest over suspected Fairford airbase plot
