Protester puts on a gas mask to prepare for a possible tear gas attack as hundreds of protesters block a main road at Hong Kong’s shopping Mongkok district

A protester puts on a gas mask to prepare for a possible tear gas attack as hundreds of protesters block a main road at Hong Kong’s shopping Mongkok district September 29, 2014. Riot police advanced on Hong Kong democracy protesters in the early hours of Monday, firing volleys of tear gas after launching a baton-charge in the worst unrest there since China took back control of the former British colony two decades ago. REUTERS/Liau Chung-ren (CHINA – Tags: POLITICS CIVIL UNREST)