Police fired water cannon and tear gas in running battles with brick-throwing anti-government protesters in Hong Kong on Sunday, the second day of violent clashes in the Chinese-ruled city.

The protesters, many in masks and wearing black, threw several petrol bombs, some taking off down narrow side streets in the pouring rain.

Water cannon have never been used until now in years of anti-government protests.

The clashes on Saturday and Sunday marked a return to unrest after days of calmer demonstrations.