Striking students are marching through Hong Kong as part of a week-long effort to demand China allow free elections in 2017.
Thousands of university students are staying away from classes all week to take part in the pro-democracy campaign.
On Wednesday, at least 300 students set out on a march that will take them through the city's central business district.
Activists have threatened to take over the district if Beijing does not meet their demands.
On Tuesday, about a dozen students scuffled with police and confronted Hong Kong Chief Executive Leung Chun-ying as he left government headquarters.
Student leaders say if Leung does not agree to meet with them by early Thursday, they will step up their action.
Pro-democracy activists were outraged after China last month ruled all candidates for the 2017 vote must be approved by a pro-Beijing committee.
Opposition lawmakers have promised to oppose the bill in Hong Kong's legislature.
China has vowed to continue the so-called "one country, two systems" plan implemented following the handover of Hong Kong from Britain to Beijing in 1997.
Under the initiative, Hong Kongers have been allowed more freedom than on the mainland, but many residents say that freedom is being eroded.