Hong Kong police fired tear gas to disperse pro-democracy protesters on Saturday after pro-China groups pulled down some of the “Lennon Walls” of anti-government messages posted in the Chinese-ruled city in more than three months of unrest.

Axar.az reports citing Reuters.

The first volley was fired when protesters hurled two petrol bombs toward an approaching police line.

Marchers converged on the town of Tuen Mun, in the west of the New Territories, where some set fire to a Chinese flag as others tore down wooden and metal fences and traffic bollards to build road blocks, at least one of which was set alight.

Some smashed fittings at the Light Rail Transit station, dug up bricks and picked up stones from the sides of the tracks. Others turned fire extinguishers on the police, who made several arrests.

“Radical protesters damaged facilities in Light Rail Town Centre Station in Tuen Mun with metal rods, hurled objects into the Light Rail tracks and set barricades in the vicinity, causing obstruction to the traffic,” police said in a statement.

“Radical protesters also threw petrol bombs, posing a serious threat to the safety of others and police officers.”

Hundreds of protesters retreated from the lines of riot police when the tear gas was fired, many sprinting across a highway to regroup briefly. Others melted away into malls and side-streets.