Two men were tied up and beaten by some radical activists during a night of clashes at Chek Lap Kok.
Anti-government protesters allowed the man to remove the makeshift barricade and reporters helped him carry the metal fence when he appeared exhausted by the effort.
The online posters apologised for the inconvenience caused to journalists, ambulance and airport staff, and stranded passengers.
A night of clashes leads to a court order banning people from gathering outside designated areas, as flights struggle to resume to normal.
Hundreds of people have occupied the area around the check-in aisles, while at least 1,000 remain in the arrivals section.
Anti-government rally organised by Civil Human Rights Front is expected to draw more than 300,000 people.
Speaking at a press conference, the Chief Executive called the city 'seriously wounded', saying it would take a long time to recover.
Ward off any unwanted visitors tonight – and for the rest of the month – by avoiding these superstitious acts.
Airport chiefs ordered all outbound flights grounded as thousands of protesters fill the arrivals hall at Chek Lap Kok.
Video footage from Sunday appears to show officers dressed as protesters injuring an arrested individual pressed to the ground.