Anti-government protesters have severely disrupted air travel for a second straight day, forcing Hong Kong International Airport to suspend check-in services for all departing flights.

Thousands of demonstrators had occupied the area around the check-in aisles from about 2.30pm, before making their way towards departure gates in an escalation of their protest, while at least 1,000 remained in the arrivals section.

While the public address system urged passengers to leave as soon as possible, many showed no sign of leaving.

A day earlier, protesters similarly prevented passengers from checking in or clearing security, forcing the cancellation of all flights in and out of the city from 4pm.