The unrest, the worst in Hong Kong since China resumed its rule over the former British colony in 1997, sent white clouds of gas wafting among some of the world's most valuable office towers and shopping malls before riot police suddenly withdrew around lunchtime on Monday, after three nights of confrontation.
"Since calm has been largely restored to the streets where citizens gathered, riot police have withdrawn," the Hong Kong government said in a statement. It called on protesters to stay calm and disperse peacefully "as soon as possible".
As riot police withdrew, weary protesters slept beside roads or sheltered from the sun beneath umbrellas, which have become a symbol of what some are calling the "Umbrella Revolution". In addition to protection from the elements, umbrellas have been used as flimsy shields against pepper spray.
Organizers have said that as many as 80,000 people have thronged the streets after the protests flared on Friday night. No independent estimate of numbers was available.
The protests, led mostly by young tech-savvy students who have grown up with freedoms not enjoyed in mainland China, represent one of the biggest threats confronted by Beijing's Communist Party leadership since its bloody 1989 crackdown on pro-democracy student protests in and around Tiananmen Square.
Cracking down too hard could shake confidence in market-driven Hong Kong, while not reacting firmly enough could embolden dissidents on the mainland, Reuters reported.
China rules Hong Kong under a "one country, two systems" formula that accords the territory limited democracy. The protesters are demanding Beijing give them full democracy, with the freedom to nominate election candidates, but China recently announced that it would not go that far.