HONG KONG (AP) — Police fired chemical-laced blue water and tear gas at protesters who lobbed Molotov cocktails outside the Hong Kong government office complex Sunday, as violence flared anew after thousands of pro-democracy supporters marched through downtown in defiance of a police ban.

A mixed crowd of hardcore protesters in black and wearing masks, along with families with children, spilled into the roads of the Causeway Bay shopping belt and marched for over 1.2 miles to the central business district. Some waved U.S. and British flags, while others carried posters reiterating their calls for democratic reforms.

Police had turned down a request by the Civil Human Rights Front to hold the march, but the demonstrators were undeterred, as they’ve been all summer.

“I feel this is our duty. The government wants to block us with the ban, but I want to say that the people will not be afraid,” said one protester, Winnie Leung, 50.

The march disrupted traffic, and many shops, including the Sogo department store in Causeway Bay, one of Hong Kong’s largest department stores, closed their doors.

Protesters burned Chinese flags and tore down banners congratulating China’s ruling Communist Party, which will celebrate its 70th year in power on Oct. 1. In familiar scenes, some protesters smashed glass windows and surveillance cameras at a subway station exit.

Hundreds of protesters later targeted the government office complex, throwing bricks and gasoline bombs through police barriers. Police responded by firing volleys of tear gas and using water cannon trucks to spray chemical-laced water as well as blue liquid that helped them identify offenders, in a repeat of confrontational scenes from the last several weeks of the protests.

Protesters retreated but regrouped in the nearby Wan Chai neighborhood, setting fires outside a subway station exit and on the streets. They fled again after riot police advanced and the cat-and-mouse battles went on for a few hours before calm returned.