HONG KONG (Reuters) – Hong Kong protesters plan to block one of the world’s busiest airports on Saturday after a night of violence in which police used tear gas and rubber bullets to break up crowds, the latest clashes in 14 weeks of unrest in the Chinese-ruled city.

Hundreds of demonstrators, many masked and dressed in black, attacked metro stations on Kowloon peninsula on Friday night, targeted because of televised scenes of police beating protesters on a metro train on Aug. 31 as they cowered on the floor.

Activists tore down signs, broke turnstiles, set fires on the street and daubed graffiti on the walls on Friday.

“The behavior was outrageous,” the government said in a statement.

Hong Kong leader Carrie Lam announced concessions this week to try to end the protests, including formally scrapping a hugely unpopular extradition bill, but many said they were too little, too late.

Saturday’s planned demonstrations include yet another “stress test” of the airport aiming to disrupt transport links to Chek Lap Kok, built in the dying days of British rule on reclaimed land around a tiny island of the same name and reached by a series of gleaming bridges.

The airport announced that only passengers with tickets would be allowed to use the Airport Express train service on Saturday, boarding in downtown Hong Kong. The train would not stop en route, on the Kowloon peninsula. Bus services could also be hit, it said.

The measures are aimed at avoiding the chaos of last weekend, when protesters blocked airport approach roads, threw debris on the train track and trashed the MTR subway station in the nearby new town of Tung Chung in running clashes with police.

Protesters also occupied the arrival hall last month, halting and delaying flights, amid a series of clashes with police.