Pro-democracy campaigners also caused chaos on the underground rail system in the morning and have called for another general strike as the three-month movement shows no sign of letting up.
The Hang Seng Index ended down 0.38 percent, or 98.18 points, at 25,626.55, with uncertainty over the China-US trade row also weighing.
The unrest is beginning to bite as tourist numbers fall, impacting a range of businesses, with property and casino companies among the worst hit.
Henderson Land shed 1.1 percent, Sino Land dived 3.39 percent and Swire Properties retreated 0.39 percent, while casino giant Wynn Macau sank 2.42 percent, Sands China fell 2.11 percent and Galaxy Entertainment dropped 1.02 percent.
MTR Corp, which runs the city's underground system, sank more than three percent.
"Protests have become more violent and tense, heightening uncertainty over how all this will end," said Philip Tse, associate director at Bocom International.
"The impression among mainland Chinese that Hong Kong is not a pleasant place to travel, or even work or go to school, could be more lasting and that will deal a substantial blow to the local economy."
There is also growing concern that China will soon send in forces to quell the demonstrations, which have drawn millions on to the streets of the semi-autonomous territory to protest against what they see as an erosion of freedoms and increasing interference in their affairs by Beijing.
"Markets are fretting on the increased likelihood of direct Chinese intervention and what that would mean for the future of one of Asia's leading financial centres," said Jeffrey Halley, senior market analyst for Asia-Pacific at OANDA.
"The answer is, not good, to put it bluntly. The economic impact will surely show in Hong Kong data going forward and may temper the mood of equity traders in Asia as the new month begins."
Shanghai's benchmark composite index rose 1.31 percent, or 37.87 points, to 2,924.11 , while the Shenzhen Composite Index, which tracks stocks on China's second exchange, jumped 2.26 percent, or 35.67 points, to 1,614.92.