Hong Kong police fired water cannons, rubber bullets and round after round of tear gas at petrol-bomb and brick-throwing protesters Sunday in some of the most widespread violence in more than three months of anti-government unrest.

Running battles in the Causeway Bay shopping district, Wan Chai bar area and the Admiralty district of central government offices followed a night of showdowns with police in the Chinese-ruled city after a peaceful pro-democracy rally turned ugly on the streets outside.

More protests are planned in the run-up to China's National Day on Tuesday, marking the 70th anniversary of the founding of the People's Republic.