Hong Kong police fired tear gas and water cannon Saturday as pro-democracy protesters threw gasoline bombs in the latest in a series of clashes that have plunged the Chinese-ruled city into its worst political crisis in decades.

Police fired round after round of tear gas and protesters took cover behind umbrellas between the local headquarters of China¡¯s People¡¯s Liberation Army and the government. Protesters also threw bricks dug up from pathways at police.

The water cannon unleashed blue-dyed water, traditionally used elsewhere in the world to make it easier for police to identify protesters later.