The “Umbrella Revolution” is not going anywhere. If anything, it is spreading.

Pro-democracy protesters again defied Chinese officials and took to Hong Kong’s streets Monday. They carried umbrellas and wore goggles to protect themselves from police batons and tear gas amid the worst unrest the former British colony has seen in decades.

The protesters had one advantage: momentum. Dramatic scenes of thick tear gas clouds and young protesters dragged away by riot police have captivated Hong Kong and the world, evoking memories of the 1989 demonstrations the culminated in the bloody Tiananmen Square crackdown. China limited reporting of the Hong Kong protests mostly to official statements that condemned them as "illegal action" and blocked images of the unrest from appearing on social media sites.

The Morning Rundown Get a head start on the morning's top stories. This site is protected by recaptcha

The U.S. expressed support for Hong Kong’s “internationally-recognized fundamental freedoms,” urging all sides to “refrain from actions that would further escalate tensions.”

“Hong Kong's stability and prosperity have long benefited from a vigorous dialogue among its citizens and a firmly established tradition of the peaceful and orderly expression of differing views,” the U.S. Consulate said. Although the statement placed strong emphasis on freedom, it added: “We do not take sides in the discussion of Hong Kong's political development, nor do we support any particular individuals or groups involved in it.”

A White House petition urging President Barack Obama to support democracy in Hong Kong and “prevent a second Tiananmen massacre” had 180,000 signatures by early Monday. “We hereby strongly appeal to the U.S. government to make it clear to the Beijing authorities that any effort to crackdown on peaceful demonstrations by force will be strongly opposed and severely punished,” it read. The British government said it was "concerned about the situation in Hong Kong" and "monitoring events carefully."

Led mostly by students, these protests have paralyzed the Asian financial hub. Organizers have said that as many as 80,000 people have thronged the streets after the protests flared on Friday night.

The number, fervor and speed with which the students came as a surprise to some. For weeks, a group called Occupy Central with Love and Peace had been planning a civil disobedience campaign. Instead of the students joining in, they led the charge; then Occupy Central with Love and Peace fell in.

The "one country, two systems" formula guarantees Hong Kong a high degree of autonomy and freedoms not enjoyed in mainland China, with universal voting rights set as an eventual goal. However, Beijing last month rejected demands for people to freely choose the city's next leader. China wants to limit 2017 elections to a handful of candidates loyal to Beijing. Communist Party leaders worry that calls for democracy could spread to cities on the mainland.

The last time tear gas was used in Hong Kong was around 10 years ago, when protests erupted around trade talks. The images of police dragging protesters in the streets have struck a chord in China and Hong Kong, where memories of Tiananmen are still fresh. It could galvanize support for the demonstrators at home and even in mainland China; despite state media attempts to ignore the protests, images are beaming into southern China.

On Monday, the protests appeared to be spreading beyond their initial flash points to the broader downtown area. Water and masks were distributed to guard against tear gas — along with new umbrellas, according to reports. "If today I don't stand up, I will hate myself in future," taxi driver Edward Yeung, 55, told Reuters as he explained his move to defy warnings that demonstrations were illegal.

Nicola Cheung, an 18-year-old student from Baptist University, said that protesters were planning what to do next. "Yes, it's going to get violent again because the Hong Kong government isn't going to stand for us occupying this area," she told Reuters. "We are fighting for our core values of democracy and freedom, and that is not something violence can scare us away from."

Reuters and Eric Baculinao of NBC News contributed to this report.