The Hong Kong police, however, said about 128,000 protesters had showed up.

The demonstration, possibly the second largest since the movement began in June, remained peaceful — a stark contrast from the violence that had broken out at previous protests.

Around the world: In dozens of other cities, including London, Toronto, Sydney, Melbourne and New York, hundreds of people also turned out over the weekend to show support for the movement in Hong Kong.

Investigation: The Times reviewed dozens of episodes in previous demonstrations involving tear gas and found that the police had at times used methods that experts describe as indiscriminate and excessive.

Beijing’s tactics: China is increasingly pressuring businesses in Hong Kong to take its side, even as their employees join the protests. The most dramatic example came on Friday, when the chief executive of Cathay Pacific Airways resigned.