HONG KONG CITY - Hong Kong airport has resumed operations after a night of chaos which saw protesters clash with riot police.

Hundreds of flights were cancelled on Tuesday after protesters flooded the terminal buildings.

Early on Wednesday flights appeared to be running as scheduled, though some still remained delayed or cancelled.

After days of disruptions, the Airport Authority said it had obtained a temporary injunction banning protesters from entering certain areas.

It said in a statement that people would be "restrained from attending or participating in any demonstration or protest... in the airport other than in the area designated by the Airport Authority".

Additional security measures have been put in place restricting access to the terminal - with only staff and passengers with valid boarding passes allowed in.

It comes as Hong Kong enters its tenth week of anti-government protests.

The airport, one of the world's busiest, has been the site of daily protests since last Friday but they had been mostly peaceful.

On Tuesday, protesters blocked travellers from accessing flights, using luggage trolleys to build barriers, and staging a mass sit-down.

Some protesters held signs apologising to passengers for the inconvenience caused by their demonstrations.

However, things escalated when one man was set upon by protesters reportedly because they thought he was an undercover police officer.

Police, wearing riot gear and brandishing truncheons, later arrived at the airport and clashed with protesters.

In one video, a policeman is seen frantically drawing his gun on protesters after being attacked with his own truncheon for manhandling a woman.(FA)