Violence returned to Hong Kong Saturday after two weeks of relative calm throughout the city. Police fired tear gas and protesters threw stones and gasoline bombs during a march against “smart lampposts” that was sparked by surveillance fears. Some protesters had pulled down and dismantled the lampposts that they said contained high-tech surveillance equipment. Police said in a statement that protesters had started fires and threw bricks at officers, and that use of force had been required to scatter the crowd. Officers also fired tear gas in a response to protesters blocking roads and aiming laser pointers at officers. The demonstrations in Hong Kong began in early June over a controversial bill that would allow extraditions to mainland China. The AP reports that the pro-democracy movement has since expanded their demands including amnesty for arrested protesters and an investigation into police violence.