Hundreds of demonstrators had earlier gathered near Maple Street Playground where protest groups had called for a rally to mark National Day.
But the playground was closed “due to the occurrence of a special incident” and there was a heavy police presence in the area. Officers were seen filming those wearing black shirts.
The protesters marched along Cheung Sha Wan Road and set up a blockade when they got to Wong Chuk Street. Police later charged down the road at them, and the protesters fled.
Protesters then blocked the intersection of Cheung Sha Wan Road and Yen Chow Street once the armed police retreated.
Soon they set things on the road on fired and vandalised government buildings, smashing the glass panels.
A protester, a university student called Angus, said he was not in the mood to celebrate the 70th anniversary of the PRC, adding that he is ashamed to be Chinese.
“Hong Kong is completely different from China. There are still a lot of people from the government talking about how China is very important to Hong Kong. But at the same time Hong Kong has its own unique features which is very different from China,” he said.
“You know when i am in foreign countries, I am ashamed to say I am a Chinese,” he said.