Police on Sunday performed security checks on public transport heading to the airport, following online calls to paralyse traffic around Chek Lap Kok. They made the move after online threats to again disrupt transport to the airport, a past target for anti-extradition protesters.

Police set up a cordon at a bus stop at a toll plaza leading to Tung Chung and began checking bus passengers. And, in an apparent show of force, a police armoured vehicle and several vans were parked nearby.

Some youngsters waiting for buses at the Lantau Link Toll Plaza had their ID checked by officers. A Mr To, who was waiting for a bus to Disneyland, had both his ID and bag checked by the police. He said officers had asked him whether he was going to the airport.

Before noon, officers with video cameras started boarding buses to look for possible protesters. Meanwhile, two water cannon trucks were seen heading towards Chek Lap Kok.

There was also a heavy police presence at various MTR stations. At the Airport Express station in Central, riot police were patrolling both inside and outside the station. Riot police were also on guard at some stations on the Tung Chung line.

At the airport itself, police officers were stationed on the passenger concourse.

The airport is operating as normal and the Transport Department says road traffic to the airport remains smooth.