Thousands of demonstrators rallied in Hong Kong's Kuen Tong district on Saturday, repeating their demand for greater democracy and protesting against recently-installed smart environmental monitoring lampposts, which have triggered privacy concerns over fears that authorities installed facial recognition technology in them.

Using electric saws and ropes, protesters, carrying umbrellas to hide their identities, brought down several lampposts, though police had told them there's no facial-recognition function in them.  

Last year, Hong Kong lawmakers approved the lampposts as part of a smart-city project. The Hong Kong government said the sensors in the lampposts only collect data on traffic, weather, and air quality.

According to the information office of the Hong Kong SAR government, the technology and devices used in the smart lamp project are mainly from local research and development institutions, including Logistics and Supply Chain MultiTech R&D Centre, Chinese University of Hong Kong, the Hong Kong Polytechnic University, City University of Hong Kong, as well as some local start-ups and middle and small-sized enterprises.

Apart from creating havoc on the street, Saturday's protests turned violent again as protesters threw bricks and Molotov cocktails at the police, who responded with batons and tear gas.

On the same day, Hong Kong's Chief Executive Carrie Lam called for dialogue, saying the continued confrontation in the city is not the way out. Lam made the appeal on her Facebook page.

The appeal came after she invited a group of people who seek solutions to the current situation to meet on Saturday morning at the Government House, the official residence of the region's chief executive, to share ideas on how to build a platform for dialogue.