Thousands of demonstrators, many in hard hats and gas masks, marched through the industrial Kwun Tong area and were stopped by the police. Some protesters launched stones from slingshots, prompting the police to charge.
The massive Hong Kong protests started in early June against a now-shelved extradition bill, which would have allowed criminal suspects to be sent to mainland China. The move was seen by dissidents as an end to the judicial freedom enjoyed by the city.
However, the civil campaign has since morphed into a broader movement seeking democratic reforms in the Chinese special autonomous region and ultimately opposing Beijing's authoritarian rule.
The protesters on Saturday faced off with the police for several hours outside a police station in Kwun Tong, having constructed barricades from bamboo poles and traffic barriers, the BBC reported.
They demanded the removal of so-called smart lampposts that authorities say are there only to measure air quality, but protesters fear could be used to implement Chinese surveillance, including facial recognition technology.
The standoff came to an end after protesters threw bricks and water bottles at the police and officers responded by charging and beating some of the demonstrators with batons.
Several protesters were detained.
Earlier in the day, some disgruntled residents and protesters confronted staff members of the railway operator, the MTR Corporation, which announced that it would temporarily shut down three metro stations at Saturday afternoon.
The move came two days after China's state-run media outlets criticized the MTR Corporation for being an "accomplice to rioters" by arranging additional trains for protesters to board during police clearance operations.
Earlier this week, Chinese Foreign Ministry spokesperson Hua Chunying shot off a series of letters to the management of some of the biggest international media houses with presence in China, accusing Washington of instigating the protests, reports say.
The letters said that international coverage of the movement was "biased". Beijing added there was evidence that US forces had been "directly involved" in "planning, organizing and inciting" violent protests in Hong Kong.
As conclusive proof of foreign intervention, Beijing presented photographs of an employee of the US consulate meeting Hong Kong opposition leaders. But China's claims clashed with Hong Kong police statements.
In a media session with international journalists hosted by the Hong Kong police in mid-August, authorities denied that foreign governments or entities had funded or organized the protests.
Washington also rejected the claims.
Meanwhile, Hong Kong leader Carrie Lam on Saturday called for dialogue, pointing out that "the continued confrontation is not the way out". She made the appeal on her Facebook page with regard to the current situation in Hong Kong.
( With inputs from IANS )