In Hong Kong streets descended into chaotic scenes again yesterday as protesters set up roadblocks and torched businesses on a main tourist drag and police responded with tear gas and a water cannon following an unauthorised pro-democracy rally.<br />''<br />''Protesters tossed firebombs and took their anger out on shops with mainland Chinese ties as they skirmished late into the evening with riot police, who unleashed numerous tear gas rounds on short notice, angering residents and passers-by.<br />''<br />''Police had beefed up security measures ahead of the rally, for which they refused to give permission, the latest chapter in the unrest that has disrupted life in the financial hub since early June.<br />''<br />''Some 24 people were injured and treated at hospitals, including six with serious injuries, the Hospital Authority said.<br />''<br />''Many protesters wore masks in defiance of a recently introduced ban on face coverings at public gatherings, and volunteers handed more out to the crowd.<br />''<br />''<span style="color: #222222;">The protest movement sprang out of opposition to a government proposal for an extradition bill that would have sent suspects to mainland China to stand trial, and then ballooned into broader demands for full democracy and an inquiry into alleged police brutality.</span><br />