Hong Kong: Cleaners swept up broken glass at the Hong Kong office of China's official news agency Xinhua on Sunday, one of the buildings vandalised in a violent day of protests which also saw activists hurl petrol bombs and set fire to metro stations.

People walk past the offices of China's Xinhua News Agency after its windows were shattered. Credit:AP

More than 200 people were arrested in one of the worst outbreaks of violence in recent weeks as around five months of protests show no signs of abating.

Demonstrators are angry at perceived Chinese meddling with Hong Kong's freedoms since the city returned from British to Chinese rule in 1997, a charge which China denies.

While protesters have previously vandalised buildings of mainland Chinese firms or those perceived as pro-Beijing, the targeting of Xinhua is one of the most direct challenges to Beijing yet. Protesters daubed China's Liaison Office, the key symbol of Chinese sovereignty, with graffiti in July.