Tertiary students in Hong Kong have joined the territory’s growing pro-democracy movement.<br /><br /> Thousands have staged a sit-in, calling on the Chinese Communist Party to reverse its refusal to allow local people to freely choose their next leader.<br /><br /> Students from more than 20 universities and colleges will this week boycott their classes.<br /><br /> Hong Kong is a former British colony that was returned to Chinese rule in 1997.<br /><br /> The city was offered a high degree of autonomy, but last month Beijing rejected demands for an election open to any candidates.<br /><br /> The student sit-in is the latest in a series of rallies against the planned electoral reform.