This photo shows streets on fire set by rioters in Hong Kong, China, on Nov. 2. (Xinhua)

Violence erupted again in Hong Kong, China, as masked rioters set fire on public properties, assaulted bystanders and threw petrol bombs towards police officers.

HONG KONG, Nov. 2 (Xinhua) -- A number of arrests have been made after masked rioters set fire on public properties, assaulted bystanders, and even repeatedly threw petrol bombs towards police officers in China's Hong Kong Special Administrative Region on Saturday.

Illegal protesters started to gather at Victoria Park, Causeway Bay, since 2:00 p.m. local time and then moved onto roads as the crowd kept growing. Most of them were black-clad and wore face masks.

The gathering was objected by the police earlier. The police said people on the scene were committing the offense of "participating in an unauthorized assembly" and a number of them were violating the face mask ban.

Police warned all protesters to leave immediately and stop occupying the road.

Over 50 bus routes were suspended and more than 100 routes were diverted.

Besides setting fire on barricades, shops and Mass Transit Railway (MTR) stations at various locations, masked rioters, who used umbrellas as cover, also hurled bricks at police officers and police vehicles in Hong Kong Island.

This photo shows rioters in bid to vandalize a Mass Transit Railway station in Hong Kong, China, on Nov. 2. (Xinhua)

Some also vandalized shops, committed arson, and placed nails on the roads.

At around 6:00 p.m., a masked rioter threw feces at police officers on Nathan Road near Granville Road.

At around 9:00 p.m., masked rioters are recklessly damaging facilities in Jordan, Yau Ma Tei and Mong Kok areas.

Some even set fire on exits of MTR Mong Kok and Central Stations and outside a shop. Some also blocked Argyle Street and Nathan Road near Yau Ma Tei with barricades and dug bricks from pavements in Jordan area.

This afternoon, several violent conflicts occurred between masked rioters and bystanders. A female was spray-painted and three men were assaulted.

This photo shows a bystander wrangling with rioters while trying to dismantle the road blocks set up by violent protesters. (Xinhua)

The police said a number of arrests have been made and dispersal and arrest action will continue. ■